22 W. & L. E. GURLEY, TROY, NEW YORK 



.t the hammer stroke is transmitted to the ear of the observer. 

 This enables him to count the number of revolutions of the 

 wheel in any given space of time, and then by means of the 

 rating table to ascertain the velocity of flow. 



Many observers perfer an electric type of revolution in- 

 dicator. In some cases it is desirable to have more than one 

 person hear and bear witness to the number of revolutions. For 

 I hi- purpose an electric indicator is preferable. To meet these 

 <l'inands, Electric Meters Nos. 617, 621 and 623 are offered. 



;. No. 616 Acoustir funvnt Mi-n-r outfit, with sleeve- jointed wading 

 rods, nilihcr tube, ear piece .ml onu.M-tion. 

 I n'lir.it ing each tenth revolution. 



In all of these patterns, the indicating device is protected from 

 injury by enclosure in the contact chambers, or commutator 

 boxes, and the revolutions of the bucket wheel are indicated 

 by a telephone receiver, which is generally fastened in a con- 

 venient position on the observer's coat. 



These meters are suspended in use by a wire or cable 

 attached to the steel weight hanger which, after passing through 



