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



The rMitial Ira hi res of a good automatic register are: 



(1) A float of sufficient area to be sensitive enough to 

 respond quickly to a change in water stage, connected to a 

 counterweight by means of a perforated band that is positive 

 in its action. 



(2) A transfer mechanism so carefully made that it per- 

 lorms all of its functions with certainty and precision. 



(3) A record sheet that is not distorted by moisture and 

 that gives the record in a form most appropriate to the use to 

 which it is to be put. This involves the cost of handling the 

 records, including provision for filing them, and of the office 

 work incident to applying the gage heights to the discharge 

 table. 



(4) A clock, of heavy yet simple construction, with a re- 

 fined escapement, compensated for temperature. 



THE FLOAT 



The value of records from water stage registers varies \\ iih 

 their accuracy, which is limited in large measure by the readi- 

 ness with which the instrument responds to slight changes in 

 the height of water. Precision in recording depends directly 

 on the amount of power required to operate that part of the 

 mechanism which records the water stage at any given instant, 

 as well as upon the time element. This power is obtained from 

 the bouyant, or lifting force, of the water acting on the area of 

 a float, that is connected by means of a perforated band to a 

 counterweight. The band passes over the driving wheel of the 

 recording mechanism between the float and the counterweight. 

 The band itself should be as light in weight as possible, con- 

 sistent with its required strength and life. The counterweight 

 should weigh somewhat more than the total weight of the band 

 and a weight sufficient to overcome the friction of the instru- 

 ment, if suspended from the counterweight side of the driving 

 pulley of the recording mechanism. Likewise, the float 

 should weigh somewhat more than the combined weights of the 

 tape, the counterweight and a weight sufficient to overcome the 

 friction of the instrument if suspended from the float side of 

 the driving pulley. 



