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



Hie combination of these features provides an outfit which 

 has been adopted as standard by the most efficient hydraulic 

 engineers. This meter is used extensively by the Water Re- 

 sources Branch of the United States Geological Survey, the 

 leading organization devoted to the precise measurement of 

 water 



The contact chambers (Commutator boxes) may be readily 

 interchanged, the only change being in the shaft and consisting 

 of the insertion of a cam on the end of the bucket shaft when 

 a single revolution is to be indicated, or the insertion of a 

 worm when it is desired to indicate every fifth revolution. 



A screw socket is provided on the frame of Meters Nos. 

 617, 621 and 623,, to receive a series of graduated rods by 

 which any of these meters may be suspended, if desired, in 



Fio. 6. Meters Nos. 617, 621 or 623, attached by a double-end banger to a 

 flush- jointed wading rod, baving a n-niovMhle base. 



stead of a cable, no change being made in the meter except 

 the removal of the weight hanger. This device is known as 

 the Covert Yoke, after its designer, Mr. C. C. Covert, of the 

 United States Geological Survey. 



The removable base for the flush-jointed wading rods used 

 in connection with a double-end hanger, serves to prevent the 

 meter from sinking into the bed of the stream. 



