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



Inimliv.lih of a foot (0.12") high for various diameters. These 

 computations show the relative power derived from floats of 

 different diameters. It will be noted that the power of the 

 float varies as the square of its diameter. 



DtuMtorof Arwof float I... r. Volume of Weight of 1 Power of weight 



AMI M qtwc in ter column cubic inch of of wain rc.lumn 



iniacfcw iackm I/ 100 foot in cuke tech** water in ounces in ounce* 



4 12.57 0.12 1.51 0.58 0.88 



6 28.27 0.12 3.39 0.58 1.97 



8 50.26 0.12 6.03 0.58 3.50 



10 78.54 0.12 9.43 0.58 5.47 



20 314.16 0.12 37.70 0.58 21.87 



In Curley water stage registers the power required to 

 operate the recording mechanism is reduced to a minimum, 

 but to insure precision and certainty of action a large float is 

 always used. 



THE TRANSFER MECHANISM 



The range of the time-keeping mechanism may be definitely 

 decided upon for any type of register. Hence, if the move- 

 ment along either axis of the register must be limited the time 

 axis may be of fixed length. Such is the case in Gurley regis- 

 ters of the graphic type, on which the records are changed at 

 fixed intervals of time. On printing type registers, however, the 

 time is transferred to the record from the faces of cylindrical 

 type wheels, which revolve with the hands of the clock contin- 

 uously for as long a time as may be desired. 



The range of water stage, on the other hand, may be decid- 

 edly variable. Hence, on graphic registers the axis along 

 which the record of stage is made should not be limited in 

 length. For this reason the record of stage should be made 

 around the circumference of the cylinder on the register. Since 

 it is possible for the cylinder to revolve on its axis, such an 

 arrangement of the axis of the record allows any change of 

 stage, no matter how great, to be recorded, each complete revo- 

 lution of the cylinder corresponding to a definite change in 

 stage. On the printing type registers the record of stage is 

 printed on the continuous record tape by cylindrical type wheels, 

 and these are made so that they may make any necessary num- 

 ber of complete revolutions. 



