L. MECHANICS AND ENGINEERING 491 



DEEPEST KNOWN WELL. 



The deepest well in the world is said to be that at Speren- 

 berg, near Berlin, which was excavated in the attempt to ob- 

 tain a supply of rock-salt. This was reached at a depth of 

 2S0 feet from the surface, and the boring was continued to a 

 maximum depth of 4194 feet, the stratum of salt having been 

 followed to a depth of 3907 feet without being pierced 

 through, and the boring then discontinued in consequence 

 of the mechanical difficulties of the operation. 18 A, Jkme 

 28,1872,379. 



WATER SUPPLY OF NISMES, ON THE RHONE. 



Iii 1866 M.Dumont presented to the Academy of Sciences 

 of Paris a sketch of a project for supplying the city of Nismes 

 with drinking-water from the Rhone, filtered naturally. In 

 1872 he announces to the same body a satisfactory comple- 

 tion of his labor, by means of which there is a daily supply 

 of over 37,000 cubic yards, or 130 gallons to each inhabitant. 

 In an industrial and scientific point of view, the importance 

 of the work just completed presents three classes of interest- 

 ing facts. First, the natural filtration of the waters of the 

 Rhone by a subterranean and lateral gallery of 555 yards in 

 length, and 33 feet wide inside, the largest known at the 

 present time. Second, the throwing up of this water by two 

 steam-engines of 200 horse-power each to a distance of 11,000 

 yards, by a single discharge-pipe of a little over three inches 

 interior diameter. This conduit, which presents numerous 

 inflections in its course, is commanded by a great reservoir 

 46 feet in height, upon which the pumps act, not directly, but 

 after having worked on small reservoirs joined to the latter. 

 The intervention of these manifold reservoirs, and the estab- 

 lishment of numerous emptiers of the air, at all projecting 

 points, have had the effect of rendering very manageable the 

 immense column of water, the weight of which is nearly 5000 

 tons, the elevation at this distance amounting to 240 feet. 



The amount of fuel required for these engines, which are 

 vertical, with direct movement, is 2.21 pounds of coal an hour 

 for each horse-power. The entire initial expense of this hy- 

 draulic arrangement, including the necessary machinery, was 

 about $1,200,000. 



