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



TYPE OF RECORD 



The hydrograph or curve recording the stage and time is 

 < oiitimious over seven days and presents graphically all <>i th< 

 Hut -Lit ions of stage and their time relations. These are slmun 

 at a glance by the curve, which is a picture record of conditions. 

 UK* advantages of this type of record are readily recognized. 



The following vertical scales can be furnished: 



Otol foot, Oto 5 feet, to 15 feet, 



to l l /2 feet, Oto 6 feet, to 20 feet, 



Oto 2 feet, Oto 8 feet, Oto 1J* meters, 



to 3 feet, to 10 feet, to 3 meters, 



to 4 feet, to 12 feet, 



A time scale of 1 day, 4 days, or 7 days can be furnished. 

 As the record of stage is made around the cylinder, there is 

 no limit to the number of revolutions possible, and hence to iln- 

 range of stage. Therefore, it is advisable to use as low a range 

 as possible and obtain a more accurate reading of the water 

 stage. If occasionally the water stage is above the nominal 

 range of the register, no trouble will be experienced in reading 

 and recording the water level. 



THE SIMPLICITY OF THE OUTFIT 



The outfit consists of a float-operated Sender located on ili< 

 river, lake, canal, reservoir, or harbor in question, and elec- 

 trically connected to a Graphic Register having a special 

 Receiving Attachment. If desired, the Sender may operate any 

 number of Registers and Indicators. 



The simplicity of the construction of these units makes them 

 very easy to install and insures satisfactory operation. 



The advantages of Register No. 637 are the same as those 

 given under Registers Nos. 633 and 636 on pages 102 to 104. 



