Cjiap. VI.

FRANCE.

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substituted for them. Perronet was desirous of perforating the piers and abutments, whichwould have added to its beauty ; but he was obliged to abandon the intention, in conse-quence of the fears entertained by some that such a construction was insecure : he returnedto this idea in the bridge of Maxence, and experience has proved that these fears werechimerical. It is a remarkable circumstance, as M. Bertrand has observed, that at the timeIVrronet was studying architecture at the Louvre, the Academy having proposed a prize fora design for a bridge to be constructed opposite the church of the Madelaine, IVrronet wasthe successful competitor.

Ills claims to public gratitude are not confined to these works: to him France wasindebted for the Canal de Bourgoyne; he also proposed to render the river Yvette navi-gable, an extremely bold project, which has been superseded by the execution of the Canalde rOurque.

During the space of thirty years, in the neighbourhood of Paris alone, more than 600leagues of road were formed and planted with trees; a vast number were widened,levelled, and rendered convenient for every kind of traffic; and before 1790 nearly2000 bridges, of various span, were placed under the superintendence of the Pouts etChaussees.

lie was appointed inspector-general of the salt works in 1757, which he held till1786.

lie invented several ingenious machines; among them a saw for cutting off the heads ofpiles under water ; a cart, called after him, which unloaded itself; a drag for cleaning har-bours and rivers; a plane table carrying a pencil; a double pump, with a continuedaction ; and an odo-metre, applicable to pumping out. This latter instrument, which mayhe adapted to all machines, shows the number of turns of the winch made by the workmenemployed, and by this means regulates the quantity of work and price ; it is also used formeasuring the distance travelled on foot or on horseback, which renders it peculiarly usefulfor military men; and it is so exact as to indicate the retrograde steps.

Perronet was a member of the Royal Societies of London , Stockholm , Berlin, Sc c., andseveral other learned bodies. The court of Russia , in 1778, desired him to prepare a designfor a bridge over the Neva, which was of a very magnificent character.

Perronet bequeathed his bust, in marble, presented by his pupils, his books, his models,&c., to the Ponts et Chaussees.

Ilis great age, and the respect his services had acquired, preserved him from the revo-lutionary tempest, and he died universally regretted in 1794.

Ilis published works consist of an account of the bridges of Neuilly , Mantes, Orleans,&c., several memoirs inserted in the Transactions of the Academy of Sciences , a memoir onconducting the waters of the Yvette and Bievre to Paris , and on the means which might beadopted to construct arches of stones from 200 to 500 feet span.

The roads formed by him and various designs were published in three volumes, folio, atthe expense of the government.

M. Lesage published, in 1805, an eloquent discourse upon M. Perronet, who may beconsidered the most distinguished civil engineer in France who had been instructedby the writings of Belidor , in which the first attempts were made to embody whatwas known of hydraulic architecture : the Italian philosophers at that time had, by theirdiscoveries, awakened in the schools of France an inquiry into the principles of science, andhad already pointed out the connection that existed between practice and the mathematicalsciences. It was not, however, the high scientific attainments of Perronet that exaltedhis name, or caused him to be the founder of a new a>ra in bridge-building, but his niceobservance of the prevailing modes of construction, which he set about reducing to asystem, and which turned to the best account the movements and employments of workmenand artificers of every denomination; he showed where labour might be saved by the in-troduction of machines, and instructed them how many difficulties which occur in laying thefoundations of buildings in water might be overcome, then unknown or forgotten.cannot turn over the engravings which represent the labours of this eminent engineerwithout acknowledging how much we owe him ; he evidently belonged to the school ofutility, upon which is now engrafted in France the refinements of mathematical analysis:those youths who now aspire to be eminent as civil engineers undergo a scrutinising ex-amination in the physical sciences, and are not admitted to the post of sub-inspector, nor arethey introduced to any practical employment, until they have shown a perfect acquirementand thorough knowledge of geometry, mathematics, chemistry, mineralogy, and the sciencesconnected with them.

The practical man is considered as the entrepreneur , or contractor, and never chargedwith the superintendence of any great work, nor is his opinion valued farther than as regardshis capability of performing what he is entrusted to execute: the design in France is left tothe learned, and the carrying into effect to the artizan.