93) Inovacoes tecnicas no seculo XX

Published by EH.NET (December 2006)

Vaclav Smil, _Creating the Twentieth Century: Technical Innovations of 1867-1914 and Their Lasting Impact_. Oxford: Oxford University Press 2005. vi + 350 pp. $35 (hardcover), ISBN: 0-19-516874-4.

Vaclav Smil, _Transforming the Twentieth Century: Technical Innovations and Their Consequences_. Oxford: Oxford University Press, 2006. vi +358 pp. $45 (hardcover), ISBN: 0-19-516875-5.

Reviewed for EH.NET by Joel Mokyr, Departments of Economics and History, Northwestern University.

It is hard to describe in a short sentence the kind of intellectual that Vaclav Smil represents. Professor of Geography and Environmental Science (whatever that exactly embodies) at the University of Manitoba, he has produced in the past decades an incessant stream of books on the technological developments of the modern age and their significance. Of those, my favorite is _Enriching the Earth_, in which he made the plausible case that the Haber-Bosch ammonia-producing process should be regarded as the invention that was as epochal as it was paradigmatic of the twentieth century. The ammonia process provided in abundance the food that was necessary if humanity was to be able to do other things and sustain even growing numbers at the same time.[1] Other books by him have discussed the energy revolution and the earth's biosphere. In these two volumes, Smil sums up what he has learned about what made the modern age. His scholarship mocks the boundaries that separate history from economics, geography from technology studies. He is unusually adept at combining his knowledge of how techniques actually work with his ability to illustrate their overall effects on society and the human condition.

The amount of pure learning and erudition that Smil brings to these 700 pages has to be experienced to be believed. In telling the story of modern technology since 1870 in a coherent way these 700 pages totally eclipse the competition.[2] Smil's writing, richly but not excessively illustrated, with a keen eye for the telling anecdote, the right illustrative number, makes his points with an eloquence and authority that has become all too rare in a world of technical scholarship in which hypothesis testing has taken precedence over a good narrative. While the narrative inevitably concerns the big breakthroughs, there are neat and cleverly presented little case studies of inventors who are anything but household names: George de Mestral, the Swiss inventor of Velcro, or Nils Bohlin, the inventor of the car seatbelt. Yet these books are anything but coffee table readings. They are thoughtful, analytical, even pensive at times. Smil full-well understands the environmental impact that the age of energy has had on the planet that unleashed it, and worries, like the rest of us, about nightmarish scenarios of the kind that Albert Gore has recently brought to every thinking person's home in America.

These volumes, in this reviewer's judgment, establish Vaclav Smil as another entry in a list of illustrious and erudite scholars whose main competence is in the History of Technology, yet who were able to lift themselves out of the quagmire of old gears and cogs to see a bigger picture, a picture of humanity struggling with the harshness of the environment and the niggardliness of nature, the deviousness of germs and the sheer violence of natural disasters. Other masters in this genre, familiar to every trained economic historian are A.P. Usher, David Landes, Donald Cardwell, Nathan Rosenberg, and Arnold Pacey. The big picture produced by Smil, it should be added, is more about the immediate effects of technology than about what it did to the economy. Smil is not much interested in the standard things that economic historians do: he uses patents for illustration (and ridicule) but does not count them, he seems to have little regard for national income statistics, and he has very mixed views about our ability to measure progress through total productivity. He does not engage in social savings calculations, and his interest in the economic models that explain economic growth is rather limited. Intellectual property rights and economic incentives hardly figure in his story at all. Oddly enough, then, this is a book that gives to economic history much more than it takes from it.

There is no real explanation of what happened. Smil's view of technology is that it is all rather inevitable; when the ideas are there and have been tested, "subsequent advances appear to have the inexorability of water flowing downhill" (I, p. 280). In the context of the Western economies after 1870 this view seems to make sense, but in fact history is full of examples in which technology did indeed freeze in its tracks for long periods, to be revived only when some further breakthrough or social change allowed it do so. Smil does not stress enough, to the taste of this reviewer, that the Western World (later to include a few Asian Tigers) was a highly unusual economic environment, in which a large number of factors had come together that were absent almost anywhere else. Conditional on that environment, progress may seem inevitable. But there was nothing inexorable about the technological blast-off in the West that is described in Volume I.[3] Indeed, Smil here and there seems to be subconsciously given to what is known as "hindsight bias" -- the notion that what happened had to happen. He has little interest in techniques that might have been but were not: the airship -- a rather substantial technological achievement at the time -- does not get a mention, presumably because it did not make it. The electric car is dismissed in one short paragraph and the steam car deserves no mention at all, even hydroelectric power barely gets two paragraphs (I, pp. 90-91). For Smil, history is definitely written backwards: start with what we have now and see where it came from. Let the economic historian who is without this sin cast the first reprint.

The two volumes here start in the late 1860s and take us all the way to the present. The first volume is dedicated to illustrate one central proposition: that the period between 1867 and 1914 -- the age that most of us refer to in our classes as the second Industrial Revolution and which Smil calls the "age of synergy" -- was the age in which the technological foundations of twentieth century developments were laid. These two generations invented most of the technology that twentieth century growth was built upon.

The second volume proceeds to tell the tale of how these seeds blossomed, in the post 1914 period, into the kind of technology that has transformed our world. Not much in these chapters will surprise a practicing economic historian teaching the origins of economic growth, but no one in our profession, I venture, is familiar with the enormous detail of technological progress that Smil provides on the sectors he is interested in. Technological progress, more than any other topic in economics, has had a certain black-box kind of nature. It is supposed to be somehow emerging as the result of the right kind of incentives and investment in human capital and R&D. It enjoys increasing returns, suffers from market failure, and in general is approximated by total factor productivity figures, patent data, and social savings computations if feasible. Smil puts a great deal of factual flesh and blood on that skimpy skeleton. Inside the black box of technological change, as he shows so richly, was a complex world of ambitious and curious creators, and greedy businessmen hoping to profit from their innovations. In the end, the consumer was the one that benefited by far the most, but, as Smil stresses, at a price.

These two volumes are not quite tantamount to a full history of technology in the second Industrial Revolution and the twentieth century. Smil is interested in energy and materials, and devotes a great deal to these favorite topics. In his picture of the world, so to speak, given enough energy and materials, we can lift the earth.[4] He also devotes much space to information processing and communications. When all is said and done, he argues, what sets our modern age apart is it consumption of fossil-fuel burning energy, which increased from 22 EJ/year to 320 EJ/year (an EJ, as some digging will reveal, is an exajoule or 10 to the 18th joules, or a very large number of very small units of energy). The average American household today, he reflects, commands about 500 kW, as much energy as a Roman landlord with 6,000 strong slaves (II, p. 260) but without the management hassles. Energy drove everything, but, as Smil reflects wistfully, it also is the Achilles heel of the entire system. There is also a long chapter on "rationalized production" in Volume II, and the development of mass production, Taylorism, Fordism, and TPS (Toyota Production System -- Smil loves acronyms, one of the few faults in his otherwise highly engaging writing style). There are some major advances that are left out, such as pharmaceuticals, genetic engineering, textiles, and civil engineering to name a few, but the areas he covers are so important and the coverage so competent and persuasive, that these are minor flaws. Underneath this improved use of energy and new materials, of course, was something deeper: better knowledge of natural processes and regularities, pure science, better mathematics, improved engineering, and networks of scientists and people of knowledge who distributed and applied a growing body of useful knowledge that made all this possible.

The two volumes are structured in similar way: the core of each consists of four chapters on specific areas of technology, preceded by an introductory chapter, and followed by two concluding chapters. The core chapters do not follow exactly the same pattern, but the overlap reflects Smil's interest and expertise. Much of the two volumes is dedicated to reproducing over and over the hockey stick effect, namely that somewhere around the end of the nineteenth century the world started to change at a high and accelerating rate compared to which the rest of human history looks rather flat.[5] Smil's hockey stick numbers are quite mind-numbing due to his virtuoso ability to pick numbers that really illustrate his points. To demonstrate the fact that new technology was biased toward destruction, for instance, he points out that the kinetic energy of a World War I shrapnel shell was about 50,000 times that of a prehistoric hunter's stone tipped arrow but the Soviet 100 Megaton of 1961 was 140 billion times that of the shell (II, p. 295).

In the somewhat tedious debate between "gradualists" and "saltationists" -- again, a discussion that every economic historian knows well from the Industrial Revolution literature -- Smil takes a firm position with the saltationists, and is not coy in actually using the term saltation. He cites H.G. Wells as noting that this was the greatest change that humanity has ever undergone, and while there was no single "shock," neither is there one at daybreak. This observation, reminiscent of the statement attributed to Edmund Burke that he could not tell when day ends and night begins, but he surely could tell one from the other, represents Smil's saltationism. His view is that between 1867 and 1914 more changed in human control over their environment and their ability to manipulate natural regularities than ever before or after, or in his own felicitous phrase (I, p. 13), "the pre World War I innovations tumbled in at a frenzied pace." Many of the great advances in productivity and product innovation were building on the discoveries of these two generations of miracles.

Much of what is wrong with the modern age is summarized by Smil in a citation from H.G. Wells from 1905 (I. p. 312): "were our political and social and moral devices only as well contrived to their ends as the linotype machine, an antiseptic operating plant, or an electric streetcar, there need now be ... only the smallest fraction of the pain, the fear, and the anxiety that now makes human life so doubtful in value."[6] In general, Smil argues, this is what bedevils the advances in technology, not the technology itself. In the closing chapters of Volume II, his earlier techno-enthusiasm seems to have cooled. Until July 1914, it seems, the human race was on a path toward progress, but then it all fell apart through violence, destruction, and collective irrationality. However, Smil is not blaming only politics and institutions for the wrong turns that technology has taken, he also pours disdain on some private decisions. For instance, he does not like cars. If a sapient extraterrestrial civilization observed the earth they would see that "wheeled organisms, besides killing annually one million bipeds ... were also responsible for very rapid climatic change and make life for the bipeds increasingly precarious" (II, p. 266). Elsewhere he heaps scorn on SUV's referring to them as ridiculously oversized, incongruous and wasteful machines (II, p. 207). Above all, he notes caustically that all the technological disasters that the twentieth century was supposed to have inflicted are dwarfed by smoking and excessive eating, and cites a study that notes that most supposedly negative consequences of technology are the result of lifestyle choice rather than environment factors caused by technical advances (II, p. 294).

There are only two serious risks that the "Great Synergy" has brought about that he thinks are worth talking about, the proven risk of armed conflicts between technologically-advanced societies, and global warming. On both of this he sounds concerned, but not alarmist. At the end of the day he concedes that the energy-intensive society that the 1880s and 1890s created cannot be sustained. He does not tell us how society can move away from this flawed system, and at times he equivocates. Thus he concludes after much fascinating technical detail in his survey of the nuclear industry that the twentieth century use of fission for electricity generation was a "successful failure" (II, p. 63), technologically successful but too costly. It is hard to see it this way from Smil's own account, because nuclear power was the only large-scale energy generation system that does not contribute to global warming, and was probably much cheaper than the solar, wind- and tidal sources that are currently discussed.

Smil is measured and balanced even when he discusses distinct technophobes like Ivan Illich and Jacques Ellul, and while he dubs Illich "an unorthodox thinker," he does not engage Illich's well-known neo-Luddite views. Smil himself is no Luddite. He is deeply impressed by the triumphs of modern technology, as he demonstrates over and over again. He knows full well that the technophobes' notions of the serenity of pre-industrial pastoral life is a risible cartoon, and that the view that industrialization deepened, rather than relieved, human misery, is "indefensible" (I, p. 299). But he is too smart and too learned to be a triumphalist. In the end, his judgment remains ambiguous and full of contradictions, much like the tale he tells so well.

Notes:

1. Vaclav Smil, _Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production_. Cambridge, MA: MIT Press, 2001.

2. The closest are Trevor I. Williams, editor, _A History of Technology, Volume VI: The Twentieth Century, part I and II_. Oxford: Clarendon Press, 1978; and Ian McNeil, editor, _An Encyclopedia of the History of Technology_, London: Routledge, 1990.

3. See Philip Tetlock, Richard Ned Lebow and Geoffrey Parker. editors, _Unmaking the West: "What-If?" Scenarios That Rewrite World History_. Ann Arbor: University of Michigan Press. 2006.

4. Even in his discussion of agricultural productivity, energy dominates the story, arguing the importance of increased energy inputs rather than improved know-how in using the sun, in a section significantly entitled "potatoes partly made of oil" (II, pp. 154-56). One might object that the oil represents stored-up solar energy, and that the increased input of energy in farming was very much dependent on improved knowledge.

5. Joel Mokyr, ""Hockeystick Economics," a review essay of Robert William Fogel, _The Escape from Hunger and Premature Death: Europe, America, and the Third World_. _Technology and Culture_, Vol. 46, No. 3 (July 2005), pp. 613-17.

6. Freud, in _Future of an Illusion_ (1927), said much the same thing: "While mankind has made continual advances in its control over nature and may be expected to make still greater ones, it is not possible to establish with certainty that a similar advance has been made in the management of human affairs."


Joel Mokyr is the Robert H. Strotz Professor of Arts and Sciences and Professor of Economics and History at Northwestern University. His _The Enlightened Economy_ will be published by Yale University Press and Penguin Books in the near future.

Copyright (c) 2006 by EH.Net. All rights reserved. This work may be copied for non-profit educational uses if proper credit is given to the author and the list. For other permission, please contact the EH.Net Administrator (administrator@eh.net; Telephone: 513-529-2850; Fax: 513-529-3308). Published by EH.Net (December 2006). All EH.Net reviews are archived at http://www.eh.net/BookReview

-------------- FOOTER TO EH.NET BOOK REVIEW --------------
EH.Net-Review mailing list
EH.Net-Review@eh.net
http://eh.net/mailman/listinfo/eh.net-review

----------------- FOOTER TO HES POSTING -----------------
HES@eh.net
http://eh.net/mailman/listinfo/hes

92) The God Delusion by Richard Dawkins

Dawkins the dogmatist
by Andrew Brown
Prospect Magazine: London; Issue 127, 2006

Incurious and rambling, Richard Dawkins's diatribe against religion doesn't come close to explaining how faith has survived the assault of Darwinism
Andrew Brown’s books include The Darwin Wars (Simon & Schuster)

The God Delusion
Richard Dawkins
(London: Bantam, 2006; £20)

It has been obvious for years that Richard Dawkins had a fat book on religion in him, but who would have thought him capable of writing one this bad? Incurious, dogmatic, rambling and self-contradictory, it has none of the style or verve of his earlier works.

In his broad thesis, Dawkins is right. Religions are potentially dangerous, and in their popular forms profoundly irrational. The agnostics must be right and the atheists very well may be. There is no purpose to the universe. Nothing inconsistent with the laws of physics has been reliably reported. To demand a designer to explain the complexity of the world begs the question, "Who designed the designer?" It has been clear since Darwin that we have no need to hypothesise a designer to explain the complexity of living things. The results of intercessory prayer are indistinguishable from those of chance.

Dawkins gets miffed when this is called "19th-century" atheism, since, as he says, the period of their first discovery does not affect the truth of these propositions. But to call it "19th-century" is to draw attention to the important truth added in the 20th century: that religious belief persists in the face of these facts and arguments.

This persistence is what any scientific attack on religion must explain—and this one doesn't. Dawkins mentions lots of modern atheist scientists who have tried to explain the puzzle: Robert Hinde, Scott Atran, Pascal Boyer, DS Wilson, Daniel Dennett, all of them worth reading. But he cannot accept the obvious conclusion to draw from their works, which is that thoroughgoing atheism is unnatural and will never be popular.

Dawkins is inexhaustibly outraged by the fact that religious opinions lead people to terrible crimes. But what, if there is no God, is so peculiarly shocking about these opinions being specifically religious? The answer he supplies is simple: that when religious people do evil things, they are acting on the promptings of their faith but when atheists do so, it's nothing to do with their atheism. He devotes pages to a discussion of whether Hitler was a Catholic, concluding that "Stalin was an atheist and Hitler probably wasn't, but even if he was… the bottom line is very simple. Individual atheists may do evil things but they don't do evil things in the name of atheism."

Yet under Stalin almost the entire Orthodox priesthood was exterminated simply for being priests, as were the clergy of other religions and hundreds of thousands of Baptists. The claim that Stalin's atheism had nothing to do with his actions may be the most disingenuous in the book, but it has competition from a later question, "Why would anyone go to war for the sake of an absence of belief [atheism]?"—as if the armies of the French revolution had marched under icons of the Virgin, or as if a common justification offered for China's invasion of Tibet had not been the awful priest-ridden backwardness of the Dalai Lama's regime.

One might argue that a professor of the public understanding of science has no need to concern himself with trivialities outside his field like the French revolution, the Spanish civil war or Stalin's purges when he knows that history is on his side. "With notable exceptions, such as the Afghan Taliban and the American Christian equivalent, most people play lip service to the same broad liberal consensus of ethical principles." Really? "The majority of us don't cause needless suffering; we believe in free speech and protect it even if we disagree with what is being said." Do the Chinese believe in free speech? Does Dawkins think that pious Catholics or Muslims are allowed to? Does he believe in it himself? He quotes later in the book approvingly and at length a speech by his friend Nicholas Humphrey which argued that, "We should no more allow parents to teach their children to believe, for example, in the literal truth of the Bible or that planets rule their lives, than we should allow parents to knock their children's teeth out." But of course, it's not interfering with free speech when atheists do it.

He repeats the theory that suicide bombs are caused by religious schools: "If children were taught to question and think through their beliefs, instead of being taught the superior value of faith without question, it is a good bet that there would be no suicide bombers. Suicide bombers do what they do because they really believe what they were taught in their religious schools." Evidence? As it happens, the definitive scientific study of suicide bombers, Dying to Win, has just been published by Robert Pape, a Chicago professor who has a database containing every known suicide attack since 1980. This shows, as clearly as evidence can, that religious zealotry is not on its own sufficient to produce suicide bombers; in fact, it's not even necessary: the practice was widely used by Marxist guerrillas in Sri Lanka.

Dawkins, as a young man, invented and deployed to great effect a logical fallacy he called "the argument from Episcopal incredulity," skewering a hapless clergyman who had argued that since nothing hunted polar bears, they had no need to camouflage themselves in white. It had not occurred to the bishop that polar bears must eat, and that the seals they prey on find it harder to spot a white bear stalking across the ice cap. Of course, you had to think a bit about life on the ice cap to spot this argument. But thinking a bit was once what Dawkins was famous for. It's a shame to see him reduced to one long argument from professorial incredulity.

91) Uma senhorita aos 70 anos

Uma senhorita aos 70 anos: a USP

A Universidade de São Paulo (USP) é a única universidade brasileira a figurar entre as duzentas melhores do mundo. Ela é responsável por um quarto da produção científica brasileira, por mais de um quarto dos doutores e por quase um quinto dos mestres. Trate-se de um bom resultado para uma instituição que completou 70 anos recentemente. Sua esperança de vida era incerta em 1934, quando foi criada pelas elites paulistas para compensar a intervenção federal depois da Revolução de 1932. No início, ela carecia de equipamentos:os professores traziam de casa tubos de ensaio. Com o surgimento das instituições de fomento, ela cresceu até chegar ao que é hoje: uma instituição exemplar.

O livro é uma coleção de entrevistas, com "massa atômica"proporcional à contribuição da USP para a produção científica no Brasil: são oito reitores, vários vice-reitores e pró-reitores de graduação, de pós-graduação, de pesquisa e de extensão, num total de 32 personalidades. Seus depoimentos podem ser lidos como uma história coletiva, com saborosas passagens sobre a vida de cada um, em grande parte filhos de imigrantes pobres que tiveram sucesso graças ao esforço pessoal, às oportunidades abertas por São Paulo e alguma sorte. Sua leitura confirma, se preciso for, que a maior riqueza de uma nação está em seu próprio povo.

A primeira parte trata de uma história que vai muito além dos 70 anos de vida oficial: são 180 anos, desde criação da Faculdade de Direito, em 1827. A introdução, assinada pelo organizador, Shozo Motoyama, começa por um sobrevôo do papel da universidade na sociedade moderna e refaz sua trajetória no Brasil, detendo-se sobre a inserção da USP na história econômica, científica e política nacional. Ela se inicia com a Faculdade de Filosofia, Ciências e Letras, que deveria fazer a junção das escolas existentes: faculdades de Direito, Medicina e de Farmácia e Odontologia, escolas Politécnica e Superior de Agricultura de Piracicaba. Foram contratados, em 1934, treze professores estrangeiros. Segundo um deles, Lévy-Strauss, seu papel mais importante não foi o ensino, mas a disciplina:os brasileiros eram bons, mas indisciplinados cientificamente. A USP foi internacionalizada desde o início, não apenas pela contribuição dos estrangeiros, mas também pelo envio dos melhores alunos ao exterior, numa época em que inexistiam as instituições de fomento. O regime de tempo integral, criado em 1946 sob iniciativa de José Reis, foi essencial para a integração do ensino com a pesquisa.

A USP acompanhou as vicissitudes da política nacional, desde os anos de crescimento otimista, na era Vargas e Kubitschek, até o renascimento democrático, em 1985, passando pelo cerceamento do pensamento, na ditadura. Alguns dos cientistas expulsos nessa fase voltaram e propuseram um Instituto de Estudos Avançados, efetivado pelo reitor José Goldemberg. Também surgiu o Centro Interunidade de História da Ciência, que veio a ter importante papel na memória da produção científica e tecnológica brasileira, refletido nesse mesmo volume. Recentemente, a USP caminhou no sentido de uma maior integração com a comunidade, inaugurando, em 2005, um novo campus, a USP-Leste.

Os três primeiros capítulos tratam do "longo antecedente"(entre 1827 e 1934), da "construção da universidade" (dos anos 1930 à ditadura, em 1969) e da "universidade resistente", isto é, os vinte anos posteriores até 1989, quando foram aprovados novos estatutos. Alguns episódios são dolorosos, como a cassação de setenta professores com o AI-5. A trajetória de resistência ao regime autoritário é contada paralelamente ao relato da gestão de cada um dos reitores, até a administração Goldemberg (1986-1990), que realizou grandes reformas. Sua maior vitória, com as demais universidades paulistas, foi a conquista da autonomia orçamentária, com a vinculação de parte das receitas do ICMS. Outra iniciativa sua, controversa na época, hoje corriqueira, foi a introdução da avaliação dos professores, responsável pelo enorme salto na produção científica.

Os ensaios históricos, cobrindo a história educacional brasileira até 1989, e os depoimentos, que alcançam nossos dias, constituem o mais amplo relato que se conhece sobre uma instituição exemplar de ensino e pesquisa, única em sua categoria pela qualidade da produção científica. O livro combina a história oral com a reconstituição do processo histórico que explica as razões desse sucesso acadêmico e científico.

Paulo Roberto de Almeida

USP 70 Anos: Imagens de uma História Vivida
Shozo Motoyama (org. )
São Paulo: EdUSP, 2006, 704 p. , R$ 120, 00

90) Ainda o problemam da Previdencia...

Reforma da Previdência - O Encontro Marcado
Fabio Giambiagi
Ed. Campos/Elsevier, 2006, 248 p. , R$ 59, 00

Para decidir

Todos que acompanham o trabalho de Fabio Giambiagi sabem que ele escreve em ritmo frenético, muitas vezes mais rápido do que a leitura é capaz de acompanhar. Seu trabalho é planejado minuciosamente e com grande antecipação. Seu livro mais recente, sobre a Previdência Social no Brasil, reflete um longo período de amadurecimento após o qual consolidada a visão do quadro social e econômico mais geral, as idéias em que se baseia podem ser expostas de forma clara e objetiva, quase sempre associadas às implicações para as políticas públicas - no caso, a necessidade de uma reforma no sistema previdenciário.

O livro é permeado por certo tom de desabafo contra as tentativas de enquadrar a questão de forma emocional ou ideológica. Para isso, Giambiagi, de forma pouco comum em obras de natureza mais técnica, expõe parte de sua história de vida pessoal para mostrar suas experiências diretas com o problema da velhice e argumentar que, não obstante toda a carga de dificuldades associada a esse período da vida, é preciso enfrentar os dilemas que a Previdência Social coloca para o futuro do país sob pena de permanecermos estagnados em relação ao resto do mundo.

O trabalho de Giambiagi sobre a Previdência nasceu de suas pesquisas sobre a política fiscal, em especial durante os anos 1990. Ali já se percebia o problema gerado pela Constituição de 1988 ao estender os direitos previdenciários a trabalhadores que jamais haviam contribuído para o sistema, ao qual veio associar-se posteriormente o impacto de fortes elevações do salário mínimo. Os dados apresentados são eloqüentes quanto ao crescimento das despesas previdenciárias no conjunto do gasto público e como proporção do PIB, e ajudam a entender por que a tributação aumentou tanto no período recente, comprometendo a expansão da economia.

O livro traz para a linha de frente do debate a necessidade urgente de reformar a Previdência Social. Os argumentos contrários à reforma, que procuram relativizar os desequilíbrios do sistema previdenciário com base em questões como o excesso de fraudes, o papel da Previdência na redução da pobreza ou ainda de que o verdadeiro desequilíbrio estaria no peso dos juros nas contas públicas, vão sendo atacados gradativamente, sempre com base em dados e utilizando uma linguagem simples. Aliás, o segundo aspecto a ser destacado no livro é que ele avança muito também na forma de apresentar os problemas, buscando comunicar- se com um público mais amplo. Das comparações com a questão previdenciária em outros países emerge claramente a distorção representada pelo caso brasileiro, onde se gasta com aposentadorias, como proporção do PIB, tanto quanto países europeus onde a parcela da população representada por esse grupo é o dobro da do Brasil. A mensagem final é clara: o país encontra- se diante de uma escolha entre o passado e o futuro, ou "entre nossos pais e nossos filhos". Certamente não é uma escolha trivial, mas dificilmente se poderia pensar num trabalho que oferecesse de maneira tão clara os elementos para que ela seja feita - ao contrário do que ocorreu no passado - de maneira consciente, avaliando seus custos e benefícios. Podemos não gostar do dilema, mas simplesmente não podemos mais ignorá-lo.

Paulo M. Levy
Resenha publicada no numero de dezembro de 2006 da revista Desafios do Desenvolvimento

89) History of Mechanical Invention (1929)

----------------- HES POSTING -----------------
------------ EH.NET BOOK REVIEW --------------
Classic Reviews in Economic History

Abbott Payson Usher, _A History of Mechanical Invention_. New York: McGraw-Hill, 1929. xi + 401 pp. (Revised edition, Cambridge, MA: Harvard University Press, 1954, 450 pp.)

Review Essay by George Grantham, Department of Economics, McGill University.

How Economic Change Happens: Usher's _History of Mechanical Invention_

Among the seminal works in economic history fewer are more perplexing than Abbot Payson Usher's _History of Mechanical Invention_. The bland title offers no suggestion of a great ambition, which is nothing less than to establish logical foundations for an empirically based explanation of economic change, the prose is stern and unrelenting, and like a car that runs out of gas just before reaching its destination, the book simply comes to a stop with no conclusion,. Few historians consult the work today. Once ransacked for information on the early history of clocks, windmills, textile machinery, steam engines and machine tools, its encyclopedic function has been superseded by more accessible and up-to-date compilations. So why should we be tempted to study it now? What gain repays the effort required to master the technical minutia of several branches of mechanics and the erudite byways of classical and medieval scholarship? The main reason is that, along with Kuznets' studies in historical income statistics, _The History of Mechanical Invention_ is a founding text of a science dedicated to explaining economic change, what Usher called the "mutual transformations taking place between human societies and their environment."

We begin with the pesky problem of how to tell that story. At the time Usher was composing the first edition of _Mechanical Invention_ (1929), the narrative of general economic history was dominated by the "stages" approach, according to which the development of individual economies is displayed in a chronological sequence of conceptually distinct types. Conceiving economies as identifiable types goes back to generalizations proposed by the ancient Greeks to interpret the customs of the strange peoples they encountered in Asia and the European hinterland. In the eighteenth century the notion received a fillip from speculations attributing the evident segregation of human societies by type to adaptation to different geographical conditions. Adam Smith's four-fold classification of societies into hunting and gathering, pastoral, agricultural and commercial economies is an unexceptional instance of this reasoning. As individual types were considered to reflect static environmental constraints, the typology contained no chronological implications, so that although Montesquieu, Smith and Turgot certainly believed that commercialized societies represented an "advanced" state of civilization, they held no strong view that it represented the latest phase of an historical sequence. Indeed, the conviction that men are physically and psychologically similar and the great prestige of Roman civilization stood in the way of a progressive narrative of social states. Reason is timeless.

In the hands of early nineteenth-century philosophers exalted by the Romantic concept of becoming, that static conception of social types acquired a temporal dimension. To position societies on the thin line of Time's Arrow, however, implied that they are discrete entities historically expressing ontogenetic development that is independent of the particular environment. But exactly what force causes such entities to cohere and persist, and drives their historical development? The cause could not be definitely stated, any more than one could then explain ontogenetic development of living organisms.[1] Whatever it was -- life-force, God's will, the national Geist, it was ineffable. It could be felt, appreciated and asserted, but not explained. All that could be declared with any degree of confidence was that each society develops through a sequence of stages marked by increasing complexity of organizational forms, methods of production, degrees of regional and occupational specialization, and movement from small to large units of social and economic organization.

In the different versions supplied by successive generations of German historical economists and American Institutionalists the stages approach provided a serviceable framework for characterizing the range of societies revealed by geographical discovery and the general trend of European development since the early Middle Ages. It was a capacious tent within which several generations of economists and historians were able to get on with the business of investigating the evolution of the myriad institutions and activities that constitute an economy without having to worry much about what it all meant.[2] Yet despite conjectures that recall elements of the New Institutional Economics, the stages "theory" offered little in the way of a systematic interpretation of how particular societies interact dynamically with their environment. It did not explain _how_ things change.

Much the same can be said of the empiricist tradition exemplified by Clapham's _Economic History of Modern Britain_ (1926). Making abundant use of contemporary statistical sources, Clapham aimed at correcting catastrophic accounts of Britain's industrial revolution concocted from impressionistic sources by asking the quantitative questions, how much, how often, and for how long. The overall impression left by this monumental exercise in error correction was that one can draw few generalizations beyond the fact of the geographic diversity of England's nineteenth-century economic experience. To the question, what happened in history, Clapham answered, many things to many people in many places. A thoughtful reviewer characterized the work as a tour book laced with numbers.[3] As Usher observed in a second review, that criticism was unfair. Clapham had an implicit model of England's industrial transformation, but left it to the reader to parse it out for himself.[4] Yet, although honest enough, this leave-it-to-Beaver approach to historical synthesis was hardly the stuff of a science capable of building on past achievements. As Darwin had observed sixty years earlier, a fact is not neutral; it is either for or against an argument. Clapham refused to argue.

Neither Clapham's sprawling narrative nor the ethereal holism of the stages approach adequately addressed the main question of how things change. Kuznets eventually resolved the problem posed by Clapham by reducing quantitative indicators of output to a scalar measure of economic activity that tracks the flows connecting income with aggregate saving and expenditure. That synthesis rests on well-understood accounting principles permitting one to speak intelligibly of an economy in time. It utilizes a measure that can be statistically decomposed to its proximate causes and even unto the causes of those causes. By contrast, synthesis offered by the stages vision of economic change achieved only an aesthetic coherence, where the significance of particular facts depended on their relation to an a priori compositional scheme. As Usher noted, the rhetorical persuasiveness is generally secured by "discreet omissions." The notion that "history," economic or otherwise can be described as the movement of a holistic entity implies the existence of an immanent principle determining the whole course of events, which makes it little more than a thinly disguised Natural Theology, where, as the Austrian novelist Robert Musil once said of allegory, "everything takes on more meaning than it honestly ought to have."[5]

Particular Systems of Events

Usher's answer to holistic history was to restrict analysis of historical causation to sequences of events for which temporal connections can be empirically demonstrated.

We ought not to say that the present is derived from the past
and the future from the present. The proposition must be
formulated in much more specific terms: every event has _its_
past. The principle of historical continuity does not warrant
any presumption about the relations among events occurring at
the same time. This assumption is very frequently made, but it
will be readily seen that it is not warranted (1954, p. 19).

Usher termed the sequences for which historical continuity can in principle be verified "particular sequences of events." Such sequences are distinct from series of events resulting from similar responses to similar situations, such as the predictable responses of economic agents to changes in the environment, because a narrative adds nothing to our understanding of them. As Paul Veyne observes,

If the revolutions of people were as entirely reducible to
general explanations as physical phenomena are, we would lose
interest in their history; all that would matter to us would be
the laws governing human evolution; satisfied with knowing
through them what man is, we would omit historical anecdotes, or
else we would be interested in them only for sentimental
reasons, comparable with those that make us cultivate, alongside
great history, that of our village or of the streets of our
town.[6]

Objects of historical thinking acquire meaning from their place in a plot that explains them. Usher held that innovation was the critical element of such plots, because it adds something that could not be predicted from initial conditions and therefore has to be explained by links to events preceding it in time.

A particular system of events must therefore be shown to be a
truly genetic sequence. It must rest upon one or more acts of
innovation that have been preserved by tradition and developed
by further innovations (1954, p. 48).

Invention, then, makes up an intrinsically historical element in a series of events. It cannot be predicted with certainty ex ante, but it can be explained ex post as a narrative of verified acts. The _History of Mechanical Invention_ proposed just such a narrative.

How does one identify a particular sequence? What principles make them distinct objects of empirical investigation? Several alternatives suggest themselves. One might distinguish events by their goal or purpose. Usher doubted that this principle could be applied to technological sequences because there are too many ways to skin a cat. The boomerang, bow and arrow, and blow-gun all kill game at a distance, but because they do not belong to the same technological system of events, none could plausibly have evolved out of any of the others. The presence of a common scientific principle suggests a better defining principle, but general principles may be too broad to define relevant boundaries identifying the particular sequence. Steam engines and steam turbines both exploit the expansion of steam to transform heat into mechanical energy, but they employ radically different mechanical means of doing it. Reciprocating piston engines descend from a pneumatic technology that originated in the hand pump; the genealogy of the turbine starts with the horizontal water wheel. The same is true of the transmission of motion by gear trains. While the devices invoked common mechanical principles in watches, clocks, and heavy equipment, the particular problems facing inventors differed so much from one application to another that the historian needs carefully to specify the context to explain the path of invention in each class of application. The boundaries of particular systems of technological events are thus narrower than their underlying scientific principles might suggest. Usher believed that the determination of those boundaries is ultimately an empirical question, as the boundaries have clearly widened over time as a consequence of advances in pure and applied science.

Systems of events consume time. Economists are not much concerned about the logical status of time except insofar as it serves as the metronome for growth theory. Not everything happens at the same time, however, and particular systems of events unfold at different speeds.
One does not see that bicameralism, coitus interruptus, the
mechanics of central taxation, the detail of rising lightly on
one's toes when uttering a subtle or strong sentence (as M.
Birotteau did), and other events of the nineteenth century must
evolve with the same rhythm.[7]

Usher held that intelligible history is necessarily pluralistic. Particular sequences, which we currently call paths of temporal dependence, demand separate treatment to track down cause and effect. A subtler problem concerns the historian's temporal perspective. Usher insisted that particular events should not be conceived as constituting the "end" of a sequence.

The temporal sequence of relations is ... incomplete unless we
think of it as a past-present-future system of relations.
Furthermore, the definition of the "present" may be taken either
from the point of view of the observer or the historian, or
from the point of view of any particular event. In fact, the
necessity of reading time series forward really commits us to
adopting a point of view in which the present is defined in
terms of the events being analyzed. It is determined by our
interests rather than by our personal position in time. We may,
thus, have knowledge of the future of a particular event, and we
may and should consider its future as well as its past (1954, p.47).

Historical sequences do not have terminal points. To understand the significance of Watt's engine is to place it in a series of events that extend backward to sixteenth-century investigations into the vacuum pump and forward towards the Corliss engine.

The Emergence of Novelty

The heart of the matter is how new things happen. By what intellectual and social processes do new methods of production, new products, and new patterns of behavior become objects of choice in the stream of economic and social life?

Historians traditionally answered this question in two ways. The first was that inventions are inspired intuition given to exceptionally gifted persons. This approach stressed the discontinuity of inventions and the importance of a small number of inventors in creating the modern world. Usher deemed it "transcendental," because in taking invention to be what amounts to a miracle, it puts the event logically outside time, so that it can have no mere historical explanation. The second approach took the opposite tack of holding that inventions occur continuously in small steps induced by the stress of necessity, somewhat like Darwinian evolution.[8] Usher termed this approach "mechanistic," because it relegated the inventor to the status of "an instrument or an expression of cosmic forces."[9] Neither the transcendental nor the mechanistic account of invention, then, was historical in the sense that explanation necessarily takes the form of a narrative. To the transcendentalist, inventions just happen (and we should all be grateful they do); to the mechanist, they occur automatically in the fullness of time. Neither explains _how_ inventions happen.

Invention is an event in the mind, so an empirically grounded model of invention should be based on its cognitive properties. The properties that Usher found most useful in this respect are drawn from the findings of Gestalt psychology, which in the 1920s was a thriving field of experimental research. Gestalt psychology proceeds from the observation that the mind commonly perceives things as wholes rather than as a chaotic flux of sensory stimuli. That perception or gestalt, however, is not an ex post "interpretation" of the stimuli; it is _how_ they are literally "seen," what Wittgenstein called a "particular organization" of sensory (visual) experience.[10] The physiological basis of this well-documented phenomenon stems from evolutionary adaptations in neural circuitry that enhanced the capacity of early hominids to quickly extract signals from a perceptually noisy environment. As those adaptations took place prior to acquisition of language, gestalt perception does not obey the cognitive constraints of propositional logic embedded in language, but conforms to the spatial logic of pictorial composition, in where things take meaning from their "fit."[11] Because of this a given stimulus can generate more than one true perception. For example, in the classic "figure-ground" form, we may see a black goblet against a white ground, or alternatively two white heads staring at each other across a black field, but never both at the same time. As the philosopher Russell Hansen put it, "There is more to seeing than meets the eyeball."[12]

Usher contended that invention is seeing a "particular organization" of data present in the inventor's mind. The gestalt paradigm opens the door to an historical treatment of invention, because what we see is influenced by our past experience, which is to say, our history. Darwin confessed that he saw the "plainly scoured rocks, the perched boulders, the lateral and terminal moraines" on his geological rambles through the mountains of North Wales, but he did not see what Agassiz had seen in Switzerland: that the eskers and eccentric boulders were the product of glacial transportation. [13] What we know limits what we are able to "see" at any point in time. That constraint imparts directionality to discovery because in time we come to know more things. But that directionality raises a further question. What happens when we see something no one has ever seen before, which by definition we do not know? In the figure-ground experiment, could we recognize the goblet rather than the faces if we had never before seen a goblet?[14] The inventor "sees" something no one has ever seen before; it has no referent. What exactly does the inventor recognize? What forces the data in his mind into a "particular organization" that makes sense?

Usher proposed that the inventor "sees" a solution to the specific problem occupying his mind at the instant of insight. The problem serves as a focal point for organizing bits of information into a pattern that potentially resolves it. Drawing on a graphical device used by gestalt theorists to illustrate the "law of closure," Usher compared the moment of insight to mentally arranging a set of broken arcs into a circle, thereby satisfying the desire for completion stimulated by the problem. The event is emotional, which accounts for the common denial by cranks that their finding doesn't work. Looked at in this way, invention is necessarily contextual, because in order to be solved the problem has to be specific enough to support a solution. When Watt was struck by the lightening bolt on Glasgow green, he was not pondering the general problem of conservation of heat; he was deliberating the concrete problem of its conservation in a specific Newcomen engine.[15] That specificity puts dates on the causal history of invention. Watt could not have posed his specific problem the way he did before 1760 because an adequate quantitative concept of heat had not yet been achieved. The balance cranes invented by Brunelleschi to hoist materials for the dome of Florence cathedral and that so impressed the young Leonardo solved the specific problem of how to safely lift stone, brick and bronze objects to the unprecedented height of 300 feet without knocking down the walls of the building it rested on. The use of pullies and counterweights goes back to antiquity; but their combination was something new made possible by a more complete mathematical analysis of the lever.[16]

In the instant of insight the elements of a potential solution to a problem come into a new relation. Extrapolating from K�hler's experiments on cognition in higher primates, Usher posited that the elements must be actively present in the inventor's mind for insight to occur. In the experiments, K�hler placed fruit just beyond a caged ape's reach, placing a baton near the animal with which it could capture the prized object. In repeated trials he found that the ape solved her problem only when fruit and baton simultaneously lay within her visual field; otherwise she remained baffled and frustrated.[17] The experiment suggests that achieving a satisfactory solution depends on serendipitous concatenation of its elements. That condition imparts significant unpredictability to the achievement of an invention, as nature rarely arranges the elements to in a form revealing a satisfactory pattern.[18] There was a large measure of luck in Edison's nervous fiddling with compressed lampblack while reflecting on his frustrated efforts to find a satisfactory filament for a light bulb.

Except in the rare instances in which inventors have left an autobiographical account of their work, the historian can rarely observe the actual moment of insight. What can be obtained from the documentation are the problems that were posed and the presence or absence of elements needed for their solution. This is usually enough to construct an explanatory narrative. Usher noted that "even at a level of incomplete verification, the historian can proceed to develop the techniques of analysis that will reveal the grosser features of the processes by which man makes himself." The invention of printing provides a good, though complex example. The elements needed to resolve the general problem of "mechanical writing" included a suitable support (paper), suitable ink (oil-based), a press (the woolen cloth calender) and moveable type. All of these elements were available by the early fifteenth century, and were being combined to make inexpensive wooden block prints by the 1430s and 1440s. The general impediment to the using of this technique to print books commercially was its inferior cost-effectiveness as compared with that of books currently being produced in specialized workshops by hand. The specific obstacle arose from the need to produce type in large numbers, which meant casting metal pieces in molds capable of holding matrices of variable size, and finding suitable materials for the matrix and metal punches. To judge from an incomplete documentation, the synthesis of the various elements that solved this problem was a drawn-out affair lasting from the early 1440s to the 1470s, of which the decisive invention was the adjustable type mold. The invention of printing was not the product of a single mind or even a single firm, but can be seen as a collective effort stretching over a whole generation. Its timing seems to be dictated not so much by an overwhelming demand for printed material, which until the price of books fell was satisfied by the output of workshops, but by the convergence of independent strands of technological know-how that suggested the possibility of substituting machinery for men in making letters.

The gestalt experiments indicate that the process of invention is strictly sequential, in that a problem must be adequately posed and the materials for its solution assembled before insight can occur. Usher identified a fourth stage in the process. Just as a new scientific finding has to be integrated into the existing stock of knowledge, so technological insight has to be translated into a working model and scaled up (or down) to the size needed to perform the desired task. Not every insight is workable. It took Watt nearly a decade to transform his insight into a commercially viable steam engine, and had it not been for the skills of Matthew Boulton's machinists and Wilkinson's boring machine, the effort probably would have failed. Usher termed that stage "critical revision." Like the other stages, it consists of many acts of problem-solving.

Because of the necessary sequencing of its events, invention uses up calendar time. At each stage problems arise that require to be solved by insight, making the system inherently indeterminate. At best, the historian can evaluate rough probabilities from objective constraints imposed by the definition of the problem and the availability of appropriate materials for its solution at a given point of time. Usher stressed that because it is drawn out invention is by nature a social process; nothing logically requires successive stages to be achieved by a single individual or within a single epoch. The idea of applying the principle of the Archimedean screw to propulsion of vessels through water was first raised by a scientist in 1729, but it took four decades of intense and expensive effort finally to bring the screw propeller to fruition in the 1840s.[19] Usher regarded such delays as the consequence of temporally definable "resistances." In general, the resistances are not social or economic, but reflect difficulties with respect to adequate formulation of the problem, the absence of one or more of the essential elements to its solution, failure to achieve the insight, and difficulties of its implementation. All of these elements are in some measure subject to verification, and thus narrated. Each makes invention time-consuming and time-dependent.

Usher's approach also supplied the means to explain the history of the economy. As noted above, optimizing adjustments by agents to preferences and material constraints do not represent fundamental change, because change comes ultimately from the introduction of novelty into a social system. Usher situated that introduction in man's capacity for problem-solving, thereby linking narrowly economic history to the broader evolutionary history of mankind. That history is not ruled by a timeless algorithm, but like the history of biological evolution rests on specific events that can in principle be identified.

[T]he act of insight does not rise above the contingency of our
knowledge upon specific contexts. Because these activities are
conditioned, analysis is possible; but because they are
conditioned they must be conceived as contingent upon the
relevant contexts. Acts of insight seek particular modes of
action or thought as a means of achieving specific ends. They
do not seek absolutes or eternal verities.

Problem-solving covers most spheres of life. Usher was particularly interested in the technological sphere; but the general approach applies to the more complex area of social problem-solving, of which the construction of economic and social policy are the most important examples. That history, however, is intrinsically more complicated and harder to pin down than the history of invention. Like most pragmatists of his day, Usher believed that the problems posed in this sphere were largely created by the technological changes that he regarded as having an autonomous history. They were not less important, for all that, just more difficult

The Proof of the Pudding

A model is only as good as its implementation. Usher implemented his model of invention through a chronological account of mechanical invention in Europe from classical antiquity to the mid-twentieth century. The selection of the mechanical band of the technological spectrum was strategic, in that the decisive technological breakthroughs driving falling transport costs and productivity growth from the seventeenth through the mid-twentieth century were mainly due to mechanization of operations previously carried out by hand and the invention of new ways of generating power. It was strategic for another reason: machines combine different techniques for transmitting and controlling motion. A study focusing on the history of specific syntheses held out the possibility of identifying the circumstances that led to the combining of "the simple but relatively inefficient mechanisms of early periods into the complex and more effective mechanisms of today" (1929, p. 67). A final practical reason was the comparative abundance of documentation.

The substantive chapters begin with a discussion of the difference between scientific and technological knowledge. Until the seventeenth century, science was, as it remains, an interpretation of the physical world.[20] But outside celestial mechanics, where the Ptolemaic system was used to calculate celestial positions, that interpretation was either too broad to identify technological opportunities, or too flawed to be of practical use. Drawing on Pierre Duhem, Usher argued that the chief impediment to scientific treatment of mechanics arose from the belief that the principles of force and motion are self-evident. "Attention was thus drawn towards logical demonstrations and mathematical theorems that involved pure reasoning rather than towards experimental study of the phenomena." Invention of devices for transmitting rotary motion and lifting heavy objects thus rested on knowledge of the strength of materials apprehended through practical experience, just as in ceramics and metallurgy. It was only from the middle of the fifteenth century that computational methods began to be applied to these problems, and it was only from the middle of the seventeenth that they acquired the power accurately to predict moments of force. From that point on, progress in mathematical analysis of mechanical problems was rapid. By the eighteenth century mathematicians and engineers were applying Newton's third law of motion and Hooke's law of elasticity to calculate the strength of materials, and using the embryonic science of fluid mechanics to compute the pressure of water on water wheel paddles and turbine blades.[21] Fulton's work on the application of steam power to water craft is an outstanding example of this work.[22] The contribution to invention was situated mainly in the stage of critical revision.

The next chapter inventories the state of mechanical technology in classical antiquity. Although classical scholarship has revised Usher's understanding of draft animal harness, the diffusion of water power, and the extent of geographical and occupational specialization, his assessment of the possibilities for invention remains sound.[23] At the end of the fourth century BC, classical civilization knew the five basic machines: lever, pulley, wedge, winch, and screw, and by the Christian era understood how gear trains translate and transmit rotary motion. As noted above, scientific analysis of these devices was not much help in designing new devices, which meant that the opportunities to combine the elemental machines into more complex devices depended on opportunities that manifested in the more immediate perceptual field. The classical presses are a good example: the beam press utilized pulleys to raise the weighted beam, while the screw press combined beam and screw. These simple combinations were closely tied to an immediate economic context setting the problem to be solved. Thus, displacement of hand mill by the rotary quern and the beam by the screw press to in the second century BC responded to the immediate problem of efficiently meeting the demand for large amounts of processed foods created by the growth of cities and trade. One can see the same dynamic at work in the invention of equipment for transporting and shaping exceedingly heavy ornamental stones.[24]

The transition to greater input of conceptual knowledge in the inventive process explains the tectonic shift in the complexity of mechanical inventions between 1500 and 1700. Early machines synthesized information obtained by visual and tactile perception (and in the case of foods, by taste and smell). Such perceptual insights are typically apprehended at low levels of generality and have been achieved many times in many places. Parallel development of lithic technology in the prehistoric world is explained by the repeated discovery that siliceous stones flake predictably enough to shape into useful forms.[25] The same was true of crafts based on manipulation of physical materials. Getting beyond that immediate level of insight, however, usually required the input of more generalized knowledge. As machines grow more complex, the physical and conceptual elements involved in achieving solutions to particular problems multiply, but as general concepts in mechanics are not immediately perceived by the senses, they are less likely to be conceived, and thus culturally idiosyncratic.[26] At this point it makes sense to compare concepts specific to civilizations as an explanation of the divergence in technological development. Usher regarded formulation of generalized scientific concepts as part of a "round-about" process of invention, in which the problems addressed are not immediately directed towards achieving a practical result. Huygens analysis of the pendulum as a means of timing the escapement mechanism in clocks is a good example.

Chapters 7 and 8 document the medieval history of two distinct branches of mechanical invention dominated by the perceptual element. The first harnessed the power of water and wind to mechanize the operations of grinding, crushing, stamping, sawing and fulling; the other captured the potential energy of gravitational force to drive and time clockwork. Both developments worked out mechanical principles mostly implicit in machines present in classical antiquity. The development of water mills and wind mills is the best documented, the critical element being the gear train translating vertical rotation of the wheel to the horizontal plane of the millstones. Gearing had been used in devices employed to measure distance and angles, but its extension to heavy-duty work was something new. One can imagine, but never demonstrate, that the idea of the water mill was taken from the gear train utilized in the cyclometer. Following an argument advanced by Lefebvre des No�ttes, and since shown to be erroneous, Usher supposed that the diffusion of water power was retarded by the deadening effect of slavery on incentives to save labor. Archaeological evidence has since demonstrated widespread diffusion of water-powered grain mills by the second century AD, which speaks volumes to the value accorded to economizing labor in the most burdensome tasks.[27] It also speaks to the wide distribution of requisite carpentering skills. The smaller horizontal and generally larger vertical mills diffused simultaneously, their geographical distribution depending on the nature of the stream and the economic advantage of high volume milling. The increased incidence of vertical wheels after 1000 AD is best explained not by technological innovation, but by opportunities for scaling up milling operations created by the growing commercialization of corn farming.[28]

Growing commercialization in the twelfth and thirteenth centuries provided incentives to apply water power to other industrial activities. The most important uses required translating the rotary motion of the water wheel into reciprocal motion used to drive bellows, stamping devices, and saws. Although Usher considered the crank and cam to be medieval inventions, Ausonius's fourth-century description of a water-powered device for sawing marble blocks in the Rhineland indicates its presence in Antiquity. As in other areas, the surviving documentation suffers from severe selection bias against evidence for its early use. Gear trains were adapted to other power sources where running water was unavailable or inconvenient. Of these the most complicated mechanism was the gearing for the windmill, which pivoted with the sail as it turned towards the wind. The most revealing aspect of the windmill, however, illustrates how purely perceptual knowledge produced inventions that achieved high levels of technical efficiency. When Euler, MacLaurin and Coriolis undertook mathematical and experimental studies of the optimal angle and shape of windmill sails in the eighteenth and early nineteenth century, they found that Dutch craftsmen had solved the problem as a practical matter by the seventeenth century.[29] As in the case of the watermill, the path of invention seems to have mainly reflected the accretion of experience under conditions of expanding demand for the apparatus.

Clockwork presents a different chronology. Timing devices controlled by the flow of water through a self-regulating float valve were more accurate than clocks whose timing was controlled by an escapement mechanism and remained in use down to the eighteenth century because they were cheaper to build and repair than the by then more accurate mechanical clocks.[30] While the invention of the escapement mechanism is obscure, its presence in clockwork is securely dated to the third quarter of the thirteenth century. Subsequent development of what was originally a massive mechanism exploited momentum of weighted bars or wheels to time the escapement and damp the recoil. Usher's discussion of these points is highly technical and directed at questions of dating. In the broader history of mechanical invention the importance of clockwork resulted from its complexity, and demands for greater accuracy giving rise to a sequence of problems that were gradually resolved by scientists and craftsmen of the highest order. An important by-product of the construction of the early tower clocks was the transfer of knowledge of how to cut and design gears from the millwrights to blacksmiths. In the seventeenth and eighteenth centuries the demand for greater accuracy created opportunities to develop gear-cutting machines that gave solutions on a small scale and for work in softer metals to problems that were to emerge on a larger scale and in iron and steel.

The next chapter considers the place of Leonardo da Vinci in the development of mechanical invention. Leonardo's role is both symbolic and real. As a symbol he marks the shift towards scientific analysis of mechanical problems (as an adult he taught himself geometry), and the use of scale models to test the apparatus (a procedure pioneered by Massacio to study pictorial composition). Of the 18,000 sheets he bequeathed to his pupil Francesco Melzi, only 6,000 have survived, and as they are not dated, it is impossible to determine the representativeness of the sample and the sequence of his thought. He invented a centrifugal pump, anti-friction roller bearings, a screw-cutting machine, and a punch to make sequins for ladies' dresses. He conceived a machine to make needles, and in 1514 was given a room in the Vatican to construct a machine for grinding parabolic mirrors to capture solar energy for boiling dyestuffs. He expected to get rich from his inventions, and was alert to potential opportunities to substitute machines for labor. He was not confident in his Latin, and of Greek he had none. He sensed that mechanisms were subject to common principles, but did not have the training to bring the abstract concepts of force and movement into focus. His workshop method of jotting down rough notes and cases was not suited to sustained trains of abstract thought. But his capacity to imagine three-dimensional mechanical connections, which his artistic training permitted him visually to describe, was unequalled. His papers circulated widely after his death, and provided ideas and inspiration to inventors for nearly a century. Usher viewed Leonardo as embodying the shift from perceptual to conceptual invention in the practical sphere of mechanics.

Save for relatively isolated cases, mechanical innovation was
empirical, realistic, and practical. Achievements of great
consequence had been realized, but by a process in which the
immediate end was ever in the foreground. It is only with
Leonardo that the process of invention is lifted decisively into
the field of the imagination; it becomes a pursuit of the remote
ends that are suggested by the discoveries of physical science
and the consciously felt principles of mechanics (1954, p. 237).

The remainder of the book, with the exception of the chapter on printing discussed above, traces out that subsequent history through a chronology of the development of textile machinery, clocks and watches, steam power, machine tools, and the development and exploitation of the turbine. As these developments are well-known there is no need here to review them here. In his account of particular inventions, often in eye-glazing and occasionally impenetrable detail, Usher was primarily concerned with showing the cumulative nature of mechanical achievement, much of it by unknown or relatively little known inventors. The development of textile machinery provided a well-documented case in point. While the increasing complexity of the material makes it difficult to reduce to an intelligible story following the lines set out in his model of invention, his broad conclusion was that the acceleration of invention in textile machinery was conditioned more by the nature of the mechanical difficulties to be overcome than economic factors. By the early eighteenth century the technical capacity and craft skills needed to overcome those difficulties were well in hand, as any visit to a well-appointed museum of technology will demonstrate. From that point on, progress depended on the way specific problems came to be posed, or not posed, and how the stage was set for insight. By the mid-eighteenth century, the increasing indirectness of invention and its rising cost made securing and protecting intellectual property rights increasingly important.

These factors are all evident in the development of the steam engine. Caus's discovery that steam is evaporated water made it possible to conceive the possibility of extracting power from atmospheric pressure by condensing steam in a closed vessel. Exploitation of that insight raised a series of technical problems associated with positioning and controlling the valves regulating the flow of steam and water. Watt's invention of the separate condenser was critical revision of Newcomen's atmospheric engine. Translating that insight into a commercially viable machine raised new problems the solution of which largely depended on the skill and experience of Boulton's craftsmen. The role of conditioning factors is illustrated by the serendipitous appearance of Wilkinson's boring machine, which machined a cylinder four feet in diameter to tolerances no thicker than a dime. The development and diffusion of the steam engine in turn led to greater use of metal gears connecting increasingly powerful engines to increasingly heavy machinery, and as the speed and force of the engines increased, the resulting stress and friction induced intensive theoretical and practical study of the optimal shape and position of toothed wheels and pinions. The sequence thus illustrates Usher's general model of mechanical invention as a sequence of problems raised and solved. We see in these developments a comprehensible narrative of how one thing led to another in the most critical region of the new technology.

The history of tools for shaping metal to high tolerances has a parallel history. The basic elements of the mandrel lathe, slide rest and lead screw were present by the end of the sixteenth century. In the eighteenth century the wooden parts were replaced by metal, increasing their accuracy and making it possible to machine heavier pieces of metal. Senot's screw-cutting lathe (1795) displayed at the Mus�e du Conservatoire des Arts et M�tiers is an outstanding example of this development, and attests its international scope.[30] Usher argued that after the substitution of iron for wooden headstocks, the principal obstacle to the development of heavy-duty machine tools was the difficulty of obtaining accurate lead screws. Here the problem was well-specified, but achieving a solution required years of painstaking work. Maudslay invented a device to correct errors of one-sixteenth of an inch in a seven-foot screw, tested the result with a micrometer, and made further corrections until he achieved the desired result. Such accuracy was essential to achieve mass-produced metal parts at low cost, though as Usher noted, the applications were initially confined to narrow fields, most notably in the manufacture of wooden pulley blocks, and firearms. Of more initial importance was use of heavy machine tools to shape large pieces of metal to the fine tolerances demanded by working parts of steam engines and locomotives. By the middle of the nineteenth century that capacity was available to be applied to a widening range of mass-consumed products like agricultural equipment, sewing machines, typewriters and bicycles. By that date the process by which specific mechanical problems were posed, the stage set and critical revision of the resulting insight carried out had become largely autonomous. It is difficult to imagine what plausible reconfiguration of relative factor endowments could have significantly affected the ensuing wave of labor-saving innovation.

The final chapter sketches out the history of the turbine, of which the applications range from more efficient exploitation of the power in falling water to the exploitation of the energy in expanding steam and gasses. Although it runs parallel to the development of the reciprocal steam engine, the story of the contemporary development of the turbine is a "particular system of events" that is entirely distinct from it. As with machine tools, investigation of impulse motors can be traced back to the early sixteenth century. The technical problems to be resolved, however, were of the highest order of difficulty, involving the invention of materials capable of withstanding extremely high temperature and rotational friction, finding optimal shapes and positions of the tubes and vans for the different media that propelled them. All this took time. Mathematical studies of turbulence relevant to the performance of turbines date to the eighteenth century; the basic breakthroughs in design by Fourneyron and Burdin date to the 1820s and 1830s. By the 1840s the accuracy of machine tools was high enough to produce a tight fit between the rotor and its casing. Parts rotating at ten to thirty thousand rpm required grades of steel that became available only towards the end of the nineteenth century; in the case of gas turbines, the materials became available only in the 1930s. The history of turbines, then, encapsulates the general trend in mechanical invention from problem-solving directed at an immediate solution with means assembled in the perceptual field to problem-solving based on scientific analysis and assembly of materials from a wide range of sources. The point is that all of this took time, and although the rough outlines of a solution might be fleetingly glimpsed, the timing of its achievement could not be predicted. The first patent for a gas turbine was taken out in 1791; a practical solution to the problem of exploiting the expansive power of heated gas in jet engines was achieved only in the 1930s.

The development of the turbine leads the discussion to the generation and transmission of electric power. The potential of large heads of water and great heads of steam could not be exploited as long as it had to be employed in situ, because no establishment could take more than a small proportion of the total power available. The invention of the dynamo and means of long-distance transmission relieved that constraint. The early development of that technology was achieved between 1830 and 1880, by which time the crucial problems had been resolved. That history, too, represents a particular system of events. The history of internal combustion engines illustrates the same pattern. An early recognition of the possibility of using the explosive power of gas in a piston (Huygens, 1680, Papin, 1690), followed a century later by patented engines (Street, 1794; Lebon (1799), lack of success for an extended period of time due to the inaccuracy of machining, difficulties of controlling the timing of the ignition and opening and closing of the valves, followed by a successful inefficient engine leading to closer analysis of the sources of that inefficiency. The sequence plays itself out as a narrative. Usher observed that from a broad perspective the history of the individual sources of power revealed a tendency to develop all possible forms of application of a general principle. The result was that by 1950 the world possessed a set of power-generating devices that spanned the gamut of weight and power capacity.

The _History_ ends with that observation. Over the course of more than 300 pages of substantive discussion, it gives an overview of the development of what was the central strand of technological development through the early twentieth century. It explains within the limitations of the documentation and the level of detail appropriate to a general overview how novelty emerged in the sphere of mechanization and the generation of power. Usher offered no conclusion to this work. Indeed, in the introduction to the second edition he noted that he deliberately avoided forcing the narrative into a preconceived mold. The _History_ was not a test of the theory of emergent novelty, only an illustration. In his later work Usher returned to the question of how to combine the insights of economics with an empirical treatment of time. He argued that "any consistently empirical interpretation of history must find some adequate explanation of the processes of change."[32] The great enemy to a rational understanding of the past in his time, as in ours, was radical idealism, which seeks to explain events by their presumed final ends or purpose.

Usher's work raises a number of problems that have been imperfectly addressed. His insights on the nature of mechanical invention are generally accepted and have been extended by historians of technology and economic historians, but the model has not been generally applied to other spheres.[33] A significant obstacle to its implementation is the extremely high degree of technical detail required to give an adequate account of any particular technological development. While detail at that level is common in the fields of political and institutional history, the desire to read such accounts is an acquired taste, though perhaps no more so than in the arcane corners of art history. As a consequence, the deployment of Usher's method by economic historians has tended to be illustrative rather than narrative and probative. The rhetorical difficulties turn on the audience to be addressed, and the level of generality required by the narrative. On the broader question of the role of time in economic processes, the picture is equally discouraging. The debate over the nature and significance of path-dependence touched analytical issues raised by Usher, but it was deflected by questions relating to dynamic optimality, which as Usher had anticipated, originate in a transcendentalist obsession with final ends. As a result, the question of what happened and how it happened got pushed aside by the question _why_ it happened. "Why" questions are intrinsically non-empirical.

Usher's focus on explaining the emergence of novelty as the special province of economic historians is nevertheless worth preserving. Bill Parker organized his lectures on economic history around the framework of challenge and response, which is just a broader way of identifying the history as a history of problems posed and resolved (or not). The problems are not just technological. The analysis of organizational and political responses to economic change can be carried out on lines similar to those that Usher considered workable for the study of scientific and mechanical invention. Some responses are comparatively easy to model using standard tools derived from the calculus of optimization; others require more contextual detail. A workable history, however, requires limiting the field to a "particular system of events" that permits a narrative account. An outstanding example of this type of economic history is Wright's account of American slavery.[34] Since the early 1960s the main thrust of economic history was directed away from Usher's concept of explanation by narration. The power of Kuznets' categories to organize numerical data provided nearly two generations of economic historians with productive work filling in the gaps and running down the tangled chains of quantifiable explanation. But Kuznets took the technological revolution as a given; the modern economic epoch was its consequence. Yet in the end, to quote one of the less illustrious figures in American history, "stuff happens." Part of the task of economic history is to find out exactly what that stuff was, and how it happened. Usher's work is a model of that type of economic history, and also shows how difficult it is to successfully pull off.

Postscript

I was distractedly browsing through my alumni bulletin this evening -- checking the latest mortalities and other alumni affairs -- when I came across the following passage in an article on Leland C. Clark (Antioch College 1941), who received the Frit J. and Dolores H. Russ Prize (the nation's stop award for scientific engineering) in 2005 shortly before his death.

Here's the story of his oxygen electrode invention.

Late one night, Clark -- then in his thirties -- was opening a
pack of cigarettes while relaxing with colleagues after
assisting in a by-pass surgery using his prototype heart-lung
machine. Although the surgery had been successful, Clark knew
that such procedures require precise monitoring of oxygen levels
in the blood. But the platinum electrode he had originally
designed wasn't working well; red blood cells were blocking the
oxygen molecules near the electrode.

What happened next was one of many shining moments in Clark's
career. "He was fiddling with his cigarette pack and suddenly
got the idea that oxygen might permeate cellophane." Soon
thereafter, Clark tried moving the two electrodes close
together, protected inside a glass tube by a cellophane
membrane. The innovation allowed oxygen to enter and be
measured with no interference from the red blood cells. To
test the new oxygen sensor he needed to find a way to pull the
oxygen out of a control solution to calibrate the sensor settings.
He added glucose and the enzyme glucose oxydase, as a catalyst,
and the oxygen was quickly removed.

Before long, however, he realized that by equipping his
oxygen sensor with a thin film of the enzyme, he could read the
decrease in the oxygen recorded in the presence of glucose.
Suddenly Clark had a simple device for measuring glucose,
also inventing the first biosensor for that purpose. Today,
electrochemical biosensors have been designed to measure
lactate, cholesterol, lactose, sucrose, ethanol and many
other compounds.[35]

One sees here all of Usher's stages in exceptional relief: the posing of the problem, the setting of the stage, the insight and critical revision, followed by extension into new problems and new solutions.


Notes:

1. Perhaps no better example of that vision can be found than in following passage composed by the aged Friedrich Meinecke in its wreckage. "Behind the growing pressure of increased masses of population ... stands the struggle for the way of life of the individual nations. By way of life we mean here the totality of the mental and material habits of life, the institutions, customs and way of thinking. All of these seem to be bound together by an inner tie, by some guiding principle from within, to form a large, not always clearly definable but intuitively understandable, unity." _The German Catastrophe: Reflections and Recollections_. Boston (1950), p. 87.

2. Erik Grimmer-Solem, _The Rise of Historical Economics and Social Reform in Germany, 1864-1894_, Oxford (2001).

3. T. H. Marshall, _English Historical Review_ 42 (1927), 624.

4. "The Application of the Quantitative Method to Economic History," _Journal of Political Economy_ 40 (1932), 186-209.

5. Cited by Veyne, _Writing History: Essay on Epistemology_, Middletown, CT (1984), 119.

6. Veyne, _Writing History_, 63

7. Veyne, _Writing History_, 26-27. The literary reference is to Balzac's _Grandeur et d�cadence de C�sar Birotteau_.

8. Mokyr appears to adopt this perspective in his evolutionary interpretation of technological change. "Like mutations, new ideas, it is argued, occur blindly. Some cultural, scientific, or technological ideas catch on because in some way they suit the needs of society, in much the same way as some mutations are retained by natural selection for perpetuation. In its simplest form, the selection process works because the best adapted phenotypes are also the ones that multiply the fastest." _The Lever of Riches_, New York (1990), 276. The proposition is defensible with respect to economic factors conditioning the diffusion of inventions. It does not explain, as Usher surely would have observed, _how_ inventions happen. Mokyr's concept of a unit technique or idea subject to selection bears an obvious resemblance to Leibniz's monad, and the sufficient reason that generates in the fullness of time the "best of all possible worlds."

9. Explaining technological change by Malthusian population pressure is an example of this kind of approach. For a recent example, see Oded Galor and David Weil, "Population, Technology and Growth," _American Economic Review_ 90 (2000), 806-28.

10. Ludwig Wittgenstein, _Philosophical Investigations_, Oxford (1972), 196.

11. See Norbert Russell Hanson, _Perception and Discovery_, Cambridge (1958), and more generally Wittgenstein, _Philosophical Investigations_.

12. Hanson, _Patterns of Discovery_, 7. A celebrated instance of dual perception was the inability of researchers to identify the cause of the potato blight, in which the fungus _Phytophthorus infenstans_ was alternatively believed to be a cause and consequence of the disease.

13. _The Autobiography of Charles Darwin_z edited by Francis Darwin, New York: Dover Publications (1958)z 26.

14. Locke reports a conjecture made to him by a French correspondent who suggested a man cured of blindness might not be able to distinguish between a box and a sphere. That conjecture has been experimentally confirmed.

15. "I was thinking of the engine at the time, ... when the idea came into my mind that as steam was an elastic body it would rush into a vacuum and might there be condensed without cooling the cylinder" (cited in Usher (1954; 71)).

16. Salvatore di Pasquale, "Leonardo, Brunelleschi, and the Machinery of the Construction Site," in Montreal Museum of Fine Arts, _Leonardo da Vinci: Engineer and Architect_, Montreal (1987), 163-81.

17. In another set of experiments with chickens food was placed outside a rectangular enclosure having an opening on one side. The hens "solved" the problem of obtaining the food only when the food and the doorway were in their line of sight.

18. The one major exception may be the "invention" of agriculture in the Near East, which most likely occurred through an improbable sequence of climatic changes that induced incipient domestication in a handful of small grains and pulses harvested in naturally occurring stands. The term invention is inappropriate in this context. See David Rindos, _The Origins of Agriculture: An Evolutionary Perspective_, Orlando FL: Academic Press (1984), and Donald O. Henry, _From Foraging to Agriculture: The Levant at the End of the Ice Age_, Philadelphia: University of Pennsylvania Press (1985).

19. The chief obstacles were intellectual, one being disbelief that a device as small as a propeller could drive a large ship, and the other concerning the optimal shape of the device in the context of extremely complex issues with respect to fluid mechanics. The history is reviewed by Maurice Daumas, ed., _A History of Technology and Invention, Vol. 2_, New York (1972).

20. Prior to the seventeenth century it also interpreted the non-physical world, as the medieval enquiry into the physics of the Eucharist amply demonstrates. On this and other topics relevant to the present discussion, see Edith D. Sylla, _The Oxford Calculators and the Mathematics of Motion, 1320-1350_, New York (1991).

21. Maurice Daumas, ed., _A History of Technology and Invention, Volume III_, New York (1979), 25-27, 81-89.

22. Fulton made countless experiments calculating the resistance to paddlewheels of varying design and to the form of the hull in relation to the weight and velocity of the engine. His work was based on Colonel Mark Beaufoy's experiments testing Euler's theorems on the resistance of fluids. This was critical revision. H. W. Dickson, _Robert Fulton: Engineer and Artist_, London (1913).

23. See my manuscript, "Prehistoric Origins of European Economic Integration."

24. J.B. Ward-Perkins, "Quarries and Stone-working in the early Middle Ages: The Heritage of the Ancient World," _Artigiano e tecnica nella societ� dell'alto medioevo_, Spoleto (1971), 525-44; Valery A. Maxfeld, _Stone Quarrying in the Eastern Desert with Particular Reference to Mons Claudianus and Mons Porphyrites_, in David Mattingly and John Salmon, eds., _Economies Beyond Agriculture in the Classical World_, London (1991), 143-70.

25. Brian Cotterell and Johan Kamminga, _Mechanics of Pre-industrial Technology_, Cambridge (1991), 127-30.

26. Within restricted ranges of perception many mechanical concepts are indistinguishable. Where friction is present, the Aristotelian theory that constant force is needed to keep an object in uniform motion is observationally equivalent to Newton's principle of inertia.

27. The archaeological evidence, which was not available to Usher, is abundant. For a compilation of European finds, see Orjan Wikander, "Archaeological Evidence for Early Watermills: An Interim Report," _History of Technology_ (1985), 151-79, and Richard Holt, _The Mills of Medieval England_, Oxford (1988). North African evidence is surveyed by David Mattingly and R. Bruce Hitchner, "Roman Africa: An Archaeological Review," _Journal of Roman Studies_ (1985), 165-213.

28. A similar transformation around the same time can be seen in the substitution in northern France of naked wheat (triticum aestivum) for spelt (triticum spelta), which being a bearded cereal costly to transport and difficult to mill was less suited to commerce. The displacement and the appearance of the vertical mill went hand in hand. See Jean-Pierre Devroey, "Entre Loire et Rhin: Les fluctuations du terroir de l'agriculture au moyen �ge," in J.-P. Devroey and J.-J. van Mol, _L'�peautre (triticum spelta): Histoire et ethnologie_, Bruxelles (1989), 89-105.

29. Daumas, _History of Technology and Invention, Volume III_, 20-22.

30. Galileo used water clocks in his experiments on falling objects.

31. Maudslay's all-metal bar lathe is dated to the same year.

32. Usher, "The Significance of Modern Empiricism for History and Economics," _Journal of Economic History_ (1949), 149.

33. I made a preliminary stab in "The Shifting Locus of Agricultural Innovation in Nineteenth-century Europe: The Case of the Agricultural Experiment Stations," in Gary Saxonhouse and Gavin Wright, eds., _Technique, Spirit and Form in the Making of the Modern Economies: Essays in Honor of William N. Parker_, _Research in Economic History, Supplement 3_, Greenwich, CT (1984), 91 214.

34. Gavin Wright, _Slavery and American Economic Development_, Baton Rouge (2006).

35. "Leland C. Clark Leaves a Medical Legacy," _Antiochian_ (Autumn 2006), 31.


George Grantham teaches economics and economic history at McGill University. He is the author of several works on the productivity of French agriculture in the nineteenth century, the macroeconomics of pre-modern agricultural societies, and the economic history of prehistoric Europe. He is presently applying Usher's concept of a "particular system of events" to reconstruct the pre-modern history of European agricultural productivity.

Copyright (c) 2006 by EH.Net. All rights reserved. This work may be copied for non-profit educational uses if proper credit is given to the author and the list. For other permission, please contact the EH.Net Administrator (administrator@eh.net; Telephone: 513-529-2229). Published by EH.Net (December 2006). All EH.Net reviews are archived at http://www.eh.net/BookReview.

-------------- FOOTER TO EH.NET BOOK REVIEW --------------
EH.Net-Review mailing list
EH.Net-Review@eh.net
http://eh.net/mailman/listinfo/eh.net-review

----------------- FOOTER TO HES POSTING -----------------
HES@eh.net
http://eh.net/mailman/listinfo/hes