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



velocity in the entire cross-section. The mean velocity, total 

 area and total discharge, are noted in the appropriate place on 

 the form. 



The preceding method of calculation may be summed up in 

 the following expression: 



L'T CfOM-Sectton ..r SMVMIU i,. 



-IMVIIU'llt 



i>is.-imrpp 



In this formula, do, di, da .... dn and vo, vi, V2 .... vn are the 

 depths and velocities at the respective measuring sections ao, ai, 

 a* .... an, which are spaced at the distances h, h, h .... In, which 

 is easily used as explained above and which gives accurate 

 results.* 



The field notes for each measurement, including a properly 

 filled in copy of sheet 1, should be fastened together securely. 

 This form, which is shown on page 54, should be filled in as 

 soon as the field notes have been computed. The computations 

 should be made before leaving the station. If the measure- 

 ment does not plot within the limit of precision established for 

 the work, the computation should be carefully reviewed and if 

 necessary the measurement should be repeated. 



It is of great importance to use the correct gage height 

 when plotting a measurement. The gage height should be read 

 at frequent intervals during the measurement, and the reading 



Fr a dlmruRKion .f <iuiiput:iti<m of di- li.n--'- imM^urrnuMits by various 

 formulas, nee nrtirlc l.y Mr. .1. < '. St.-v.-n-. M. Am. Soc. ('. K.. in I-:nu'in-.T:ir_' 

 News, June 25, 1908. 



