454 MARQUIS OF CALIGNY. 



Its living force attains its maximum at the instant when the liquid 

 in the pipe rises to the reservoir level. This living force is capable, 

 except for the slight loss due to friction, of carrying the ascending 

 liquid column as high above the reservoir level as its point of depart- 

 ure was below it. As only a part of the force has been consumed at 

 the moment when the liquid begins to pour out above, the discharge 

 continues until the whole column in motion has been brought to rest. 

 But at this moment the valve falls by its own weight, and opens at 

 the same time a short horizontal tube which it closed while it was 

 raised, thus offering a free exit for all the water in the vertical pipe, 

 which thus rapidly escapes into a second reservoir just above the 

 level of the valve. The liquid contained in the horizontal conduit 

 during this time comes to rest, and then begins to oscillate by raising 

 the valve ; then a new period of asceusiou with discharge begins." 



If Caligny's experiments had not been realized for half a century, 

 might not this description have been taken as a project for perpetual 

 motion ? 



In 1868, the Administration of Roads and Bridges built, on a work- 

 in<r scale, Caligny's new system of saving basins for canal locks, at the 

 Aubois Lock, upon the lateral canal of the Loire. 



Here he made many experiments with the help of the Administra- 

 tion. Inspector General Valles accompanied him, made a report to 

 the Institute, and published a memoir entitled, " Experiments made 

 at the Aubois Lock to determine the useful Effect of the Apparatus 

 by the aid of which M. de Caligny greatly diminishes the Consumption 

 of Water in Navigable Canals." 



The following description of this apparatus is taken from the 

 United States Report* on the Vienna International Exhibition. 



Description of the Aubois Canal Lock. 



Process invented by the Marquis of Caligny. — We know that for each 

 passage through a lock, whether up or down, a quantity of water must be 

 drawn from the upper bay to fill up the lock to a height equal to the 

 difference of level between the two bays, this height being called the lift 

 of the lock, and the volume of water required for this purpose the prism 

 of lift. The system invented by the Marquis of Caligny and applied to 

 the Aubois lock has for its object to diminish this waste by causing 

 water from the lower bay to ascend into the lock-chamber when the latter 



* Civil Engineering, Public Works, and Architecture. By William Watson, 

 U. S. Commissioner. 



