496 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



American Institute Polytechnic Association, 



Aj^ril 2, 1863. ( 

 The Chairman, S. D. Tillman, Esq., presiding. 

 Mr. Bull read an extract from a paper giving an account of 



The Sewers of Paris. 



" The first vaulted sewer in Paris was constructed as early as 

 1374; but so slow was the progress of the improvement that the last 

 uncovered sewer only disappeared ten years ago. The present system of 

 sewerage was decreed on the 26th of March, 1852, and consists of six 

 main galleries, called collectors; fifteen secondary ones opening into the 

 former, and themselves fed by a vast number of smaller ones intersecting 

 the city in every direction. 



" The smallest sewer is some seven feet in height, by four in breadth, and 

 the largest about thirteen feet in height and seventeen in breadth. The 

 former is of an ovoid shape, and affords ample space for a man and a wheel- 

 barrow. The largest sewer is divided into three parts, the two lateral 

 ones forming foot pavements and the middle one a gutter or drain some 

 four feet broad. On each foot pavement a series of iron posts support a 

 water-pipe, varying in diameter from three a7id a half to two feet. In 

 some of the galleries there is but one water pipe. To cleanse the drain a 

 small cart running on iron rails laid along the bottom is pushed for- 

 ward by two men; the front of this cart is provided with a drop-plank, 

 acting like a sort of sluice, which, when down, exactly closes the section of 

 the gutter, and pushes all the mud before it as the cart advances. 



"But the grandest feature of this sewerage system is a syphon by which 

 the foul waters of a large part of the city are carried under the bed of the 

 Seine to a proper outlet. This syphon is an enormous pipe of wrought 

 iron, having an interior diameter of three and a third feet, and some seven 

 hundred feet in length, which is sunk seven feet below the low- water mark. 

 The general collector, into which all the secondary ones pour their floods, 

 is a stupendous work, and probably without a parallel in the world. It 

 is sixteen feet in height by eighteen in breadth, with a length of about 

 eighteen thousand and forty-five feet in nearly a right line. The foot pave- 

 ments in this immense subterranean avenue are some six feet, the central 

 drain is nearly eleven feet in breadtli, with a depth of five feet; so large, 

 in fact, that a well-sized boat is kept afloat on it fur the purpose of cleans- 

 ing. Four boats in all are constantly employed in this work, and it takes 

 sixteen days to cleanse the whole length. Ventilation is provided for by 

 air-traps at certain distances, and the gallery is lighted with oil lamps. 



"The execution of this immense sj'stem of sewers has cost fifty millions 

 of francs ($10,000,000). The grand gallery is larger than the famous 

 Cloaca Maxima of Rome, while the style of construction is of course vastly 

 in advance of the Roman work. The Cloaca Maxima is over thirty feet in 

 height, but is only tliirteen feet broad, and is supposed never to have ex- 

 ceeded a length of three thousand^feet." 



The Chairman. — In connection with the subject of sewers, I may state 

 that one of the largest sewers in the world is now building in London. 

 The city of New York, owing to its natural advantages, does not require 



