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Engineer Bridges and causeways

Purchased earlier in this book in a bookseller promising title: Viaduct Erdre. Treaty practice for construction of steel bridges arched by Mr. Ch. Dupuy, Chief Engineer of Roads and Bridges in charge of the Company's service of Orleans, with the assistance of Mr. Stephen Lauras, civil engineer, alumnus of Central School, assistant engineer at the Orleans Company, Paris, Dunod Publisher, 1879.

Save the date: 1879, three years before the commencement of construction of the viaduct Garabit by Gustave Eiffel. We caught the monumental work of someone who represents the engineer-hero of the late nineteenth century rather than the obscure MM calculations. Dupuy and Lauras. It is true that the viaduct Erdre is much more modest - the main span arch measuring 95m, 165m to Garabit cons (of 564m in all) and is about twenty feet above the water, what is there so much less dramatic than the mountains cantaloupes. The viaduct Erdre is also certainly not the first of its kind - after all, we built a viaduct arch over the Severn, beams cast iron and not exactly a century earlier. The authors did not, moreover, that claim, only to publish the calculations they had employed so that their successors can enjoy this experience.

From calculations: it is what it is. I admit I vaguely hoped, by buying this little book on the Seine, find some implementation plan, perhaps even prints of the work. But the content is this: formulas, tables of values to be used in such formulas; few diagrams to explain these calculations (see page among others, shown more than average and it is taken into account the constraints of expansion). The lover of beautiful drawings (I am) is disappointed, but not the historian of technology, here is a magnificent example of what became the science of engineering in the aftermath of the Second Empire.

This science, he had been born with a view to Belidor Bernard Forest in the 1720s (see Langin, Conserving the Enlightenment , Chapter 9), which sought to establish rules for calculating the construction of fortifications. "The structures, he said, must draw their strength of workmanlike rather that the abundance of materials. She is now in full possession of his means, to the point of feeling able to accurately predict the behavior of a structure of a new type. The material is indeed suitable for calculation, with beams that work only in the direction of the length - to the point that one wonders if the success of the structures "eiffelliennes" does not come primarily from their adaptation for engineering calculations.

Science Engineering is a science of calculation and prediction. But it is also an experimental science: this project is a bench trial, where the measures taken have confirmed the a priori calculations . And, of course,

Whatever this respect the views of manufacturers, we believe that the discussion in which we delivered demonstrates the confidence that should inspire the arch span. Certainly study projects is not difficult, and the results which lead calculations are maximums which, in practice, will never be achieved.

and Laura Dupuy, op. cit. , p.78.

Bridge Erdre may well be a bit forgotten, if indeed it still exists (and there Nantais in the room? This must be the bridge Jonelière, just left of the highway bridge Beaujeoire going to Chapelle-sur-Erdre) - but it represents an example of the engineering triumph of the late nineteenth century. It is not nothing anyway!

[NES, January 30: A nice reader Nantes confirms that it is the bridge Jonelière but was destroyed by the Germans in 1944 and rebuilt in concrete in 1948 . His comment see below.]

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Two interesting books

stumbled into a library two interesting books:

Janis Langin, Conserving the Enlightment, French Military Engineering from Vauban to the Revolution , MIT Press, 2004, 532pp.

The title is a response to Ken Alder, Engineering the French Revolution , who claimed to find a quality intrinsic to the emergence of revolutionary figure of the engineer in the eighteenth century France. Janis Langin from a subject he knows well: the controversy between the Corps of Engineers and the Marquis de Montalembert on the ideas of the latter in terms of fortification. It organizes around a story of this episode of the thought of military engineering and body engineering, it shows the emergence in this context the concept of science for engineers. It remains a practical science whose main purpose, strength and safety of built structures, encourages the continuation of proven methods.

admit not being sure that the book Alder certainly interesting (and sometimes horrifying, it must be said), deserves to polarize the debate at this point - in any event, here we are with a recent history well kept and engineering in the eighteenth century, both the organization of military engineers of scientific thinking and the mentality of a body art. In addition, work on the controversy Langin fortification perpendicular undertaken for years, deserved to be published in book form. Well, a couple of balls on Metallurgical de Montalembert, but ultimately less than the deplorable bio that was published last year by a local scholar.

Chris Evans and Göran Rydén (eds.), The Industrial Revolution in Iron, The Impact of British Coal Technology in Nineteenth-Century Europe , Ashgate, 2005, 200pp

Collections articles of this type are sometimes passable, other times mediocre (the syndrome of publish or perish ) but sometimes they do more forward thinking than a brick of a single author. This is the case of the latter, edited by two eminent representatives of a new generation of historians of technology - I heard Chris Evans at the conference on steel, CNAM, it was brilliant. He will go far, this little guy. Finally, rather large, actually.

What they're saying, collectively? What if, as we know, the technical changes occurred in Great Britain for the production of iron had a fundamental influence on European industry, this influence has a story - it is not immediate, it is not complete, it goes without saying. There is not a "technical revolution" that overnight returns the old processes to the rank of survivals, but rather the contributions vary according to regions considered in terms of local technical culture. It seems obvious, but it has not been studied that much. What interested the first generation of French historians of technology, those 50-60 years is the emergence of the technical system which then triumphed with the creation of the ECSC and peak production thirty glorious. This book shows how the story is more subtle, and how much space remains to be explored if we are willing to turn from the "idol of origins" (to use one of these forms of Marc Bloch that we do not meditate enough).

short, with these avenues of research, here we are with the job for twenty years. Well, let's go!

Well, not everything, but Feather's research, companies are also in years, they deserve to be written, too!

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Installation

You will find here the entries in this category that was my story said on 20six. I copied the entries as shown, one or two typos closely, there are some entries where I broke down and added little notes in brackets.

To follow, of course.

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Apology for history

Probably the only book on the historian's practice of history that I reread continually piecemeal: Apology for history or art historian Marc Bloch - undoubtedly the founder of historical science as we practice it today. The book is unfinished, the author, resistant, was among the victims of Klaus Barbie, it was published by his friend Lucien Febvre in 1949. It is a wonderful book

- everything is there, almost to the point we could just quote piecemeal. Here, on the question of vocabulary, already mentioned here methinks, and so powerful in the history of technology (what words to use, those of our sources or ours? And how not read the words of our sources as they were ours?), a phrase

For, much to the chagrin of historians, men are not accustomed, whenever they change their habits, change of vocabulary.

I'll stop there; quote Marc Bloch is like eating pistachios, once you start, you can not stop.