20 



HYDRAULICS. 



has failed of producing very advan- 

 tageous effects. 



The Water Ram or Belter Hydrau- 

 lique, as it was called by its inventor, 

 M. Montgolfier, of Paris, is a highly 

 useful and simple machine, for the pur- 

 pose of raising water without the ex- 

 penditure or aid of any other force than 

 that which is produced by the momen- 

 tum or moving force of a part of the 

 water that is to be raised ; and is one 

 of the most simple and truly philoso- 

 phical machines that Hydraulics can 

 boast. The action of this machine de- 

 pends entirely upon the momentum 



that is generated whenever a body is 

 put into motion, and its effect is so 

 great as to give the apparatus the ap- 

 pearance of acting in defiance to the 

 established laws of Hydrostatic equili- 

 brium ; for a moving column of water 

 of small height is made to overcome 

 and move another column much higher 

 than itself. 



The form and construction of the 

 Water-ram is shown at Jig. 16. Sup- 

 pose o to represent a cistern or re- 

 servoir, or the source of a spring 

 which is constantly overflowing and 

 running to waste, by means of a chan- 



nel a few feet lower than itself, as at 

 the level line p p. Instead of per- 

 mitting the water to run over the sides 

 of o, let it be conducted to the level 

 p p, by means of iron or other pipes 

 q q connected with the side of the re- 

 servoir, and terminating by an orifice r, 

 in which a conical or other valve s, is 

 placed so as to be capable of effectually 

 closing the pipe when such valve is 

 drawn upwards ; t is an adjustable 

 weight fixed on to the spindle of the 

 valve s, by means of which the valve is 

 kept down and open ; any water there- 

 fore that is in the cistern o will flow 

 down the pipe q q, and escape at the 

 orifice r, so long as the valve remains 

 down, but the instant it is raised and 

 shut, all motion of the water is sus- 

 pended. Thus situated, the adjustment 

 of the weight t must take place, and by 

 adding to or subtracting from it, it must 

 be made just so heavy as to be capable 

 of sinking or forcing its way down- 

 wards, against the upward pressure of 

 the water, the force of which will de- 

 pend upon the perpendicular distance 

 from the surface of the water in o, to 

 its point of discharge at r, (represented 

 by the dotted line o v). But tha water 



by moving acquires momentum and 

 new force, and consequently is no 

 longer equal to the column o v, to which 

 the valve has been adjusted, but is su- 

 perior to it, by which it is enabled to 

 overpower the resistance of the weight 

 t, and it carries the valve up with it, 

 and closes the orifice r. This is no 

 sooner done than the water is con- 

 strained to become stationary again, by 

 which the momentum is lost, and the 

 valve and weight once more become 

 superior, and fall, thus re-opening the 

 orifice and permitting the water to 

 move again ; and as the pressure of the 

 water and the weight of the valve each 

 become alternately superior, the valve 

 is kept in a constant state of vibration, 

 or of opening and shutting without any 

 external aid whatever. "Such is the 

 principle upon which the motion of the 

 water in the pipe q q is produced : but 

 the momentum generated cannot be 

 instantly annihilated ; and it is not only 

 of sufficient power to raise the valve s, 

 but likewise to burst open the lower 

 end of the pipe q q, unless a sufficient 

 vent be provided by which this accu- 

 mulated force can escape. Accord- 

 ingly a second valve u is placed near the 



