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



otiinate of high water conditions can also be made, while at 

 medium and high stages it is usually impossible to examine the 

 bed or estimate low stage velocities. A stream in a lumbering 

 -i-i-iioM muM be watched closely during the log-driving period. 

 Locations at which log jams usually form should be avoided. 



\\ln-n the problem of locating stations involves an rut in- 

 drainage basin, an hydraulic engineer familiar with the basin 

 \\ill likely have in miml tentative locations for the primary 

 station and for supplementary stations, and will extend hi- 

 reconnoissance by making examinations at different river stages 

 at numerous points in the basin as he may have occasion to 

 go back and forth in it. For locating secondary stations care- 

 ful reconnoissances are also required, but they are usually 

 made more rapidly. 



If the project for which the data are collected depends on 

 continuous flow, and there are few or no storage possibilities, 

 the essential data will be that giving the amount of the minimum 

 flow, and the period for which it continues. If opportunities 

 for storage do exist, then the maximum flow will be of equal 

 importance. Satisfactory results are usually obtained if these 

 two extreme conditions are allowed to determine the location 

 of the station. 



The following essentials should be carefully examined: 



1. The general course of the stream above, at and below, 

 the station, noting whether the course of the stream is straight 

 or whether curved. 



2. The average depth and velocity of the stream at the 

 section under consideration. 



3. The character and location of the control point, with 

 reference to the proposed location of the gage. 



4. The character of the stream bed, whether of sand, 

 gravel, boulders or rock, and especially whether it is shifting 

 or permanent. 



5. The character of the stream banks at the proposed 

 section, whether high or low, clear or wooded, permanent or 

 changing. 



6. The relative position of dams and the mouth of tribu- 

 tary streams relative to the proposed location, considering 



