WILLIAM SIEMENS, F.R.S. 279 



Several years since (in 1845), the writer of the present paper 

 imagined a meter by area of channel, which dispensed with the 

 necessity of a cistern, and registered the quantity of water actually 

 passed through. It is shown in Fig. 2, Plate 24, and consisted of a 

 piece of square pipe A, containing a common flat valve B, which 

 the water has to raise in order to pass through. The spindle of 

 this valve passes through a stuffing-box, and carries the lever C, 

 which by its motion raises or lowers a driving strap D, upon the 

 reversed cones E F. The cone E receives a regular motion by 

 means of a clockwork G, while the cone F communicates the 

 motion received through the strap to a counter at H, with a dial 

 plate I ; if no water passes through, the valve B rests at the 

 bottom, and the clockwork is entirely stopped by means of a 

 detent K; the instant the valve B is raised by the passage of 

 water, the clockwork is released, and imparts a very slow motion 

 to the counter : but in proportion as the flow increases, the strap 

 rises, and the motion of the counter is increased. A correct 

 registration is thus obtained, provided the elevation of the 

 flap-valve is proportionate to the amount of water passing 

 through, which is practically the case, since the constant weight 

 of the valve itself renders the velocity of flow under its edge 

 constant. 



A meter differing only in the details from the above has recently 

 been brought out by Mr. Kennedy, of Kilmarnock. 



The frequent necessity for winding up the clock movement 

 rendered this meter evidently unfit for general application. To 

 obviate this, the writer thought of abstracting the motive power 

 for the clock from the water itself, by introducing a screw propeller 

 into the pipe. 



Being advanced thus far, it became apparent that the valve 

 and clockwork might be entirely dispensed with, if the propeller 

 could be made to rotate in the precise ratio of the moving 

 column of water, and to impart that motion directly to the 

 counter. 



Thus the first step was made toward the production of a 

 " Meter by Impact," by which it is contended the conditions 

 above enumerated of a perfect meter are most fully realized. 



The writer considers it an essential condition of a " Meter by 

 Impact," that the propelled vanes merely glide edgeways through 



