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



ol the center of the cups. On the upper end of the top rod 

 1 1 KIV is a flat plate (52) in the center of which there is a hole 

 thmimli \\liirli the sound from the drum can be heard. The 

 soundings are made with this end of the rod, and the plate keeps 

 the rml from sinking into the bed of the stream. 



The meter cables must be strong enough to support ih 

 weight required to hold the meter in place while making obser- 

 vations, must be water-proof to avoid short circuits and must 

 be tough and flexible to withstand hard usage. They should 

 be as small in diameter, consistent with strength, as is possible, 

 in order to offer small resistance to the water. They may be 

 graduated in feet by means of markers, for convenience in 

 measuring depths. Greater precision in such measurements is 

 obtained by using a single index point and applying it to a 

 fixed scale. This method eliminates the effect of any possible 

 stretch in the cable. When used on a cable reel, (See Fig. 2) 

 the scale and index are part of the reel. 



Reels should be used at any place where a considerable 

 number of measurements are to be made, both as a matter of 

 convenience in handling the equipment and to protect the elec- 

 tric circuits in the meter cable from the effects of twisting and 

 abrasion. 



J Reel for use with Gurley Current Meter Designed for use on a 

 railroad bridge lumng a narrow foot walk. The reel is fastened on 

 the side opposite the meter, so as t prevent it from tipping. 



