THE(")KK rUAI, AND MEASURED PlIMFINi; POWER IW WINM )MI EI.S. 



velocity measurements were made on the top of the water tank 

 twent}^ feet below the platform and the velocity v at the platform 

 found from the formula 



'i\l^ 



-72 



+ 72 



The velocity and corresponding number of strokes of the pump 

 were found by reading the meter when disconnected or when the 



Fig-. 5.-10 ft. wood mill. 3t ft.-llis. per stroke, 

 minute glass was horizontal, then throwing it into gear by turning 

 the glass upright, and counting the number of strokes while the 

 sand was running throtigh. or in 58 seconds, then disconnecting 

 and reading again. //?(5^' 

 The difference of the 

 readings gave the dis- 

 tance traveled by the 3'(^ 

 wind in the 58 sec- 

 onds. From twenty 

 to ninety such meas- ^00_ 

 urements were made 

 with each mill. 



These m easu re- ^ 



ments are represented '^ «'^ <2»t? 30 J'-* 7^ 



diagram atically on ^''-- ''-i" ^^- "^^^^" "^"'- ''••' ^^-i''^- »'"■ ^^^"^'''■ 



Figs. 4 to II. The center of each little circle or star represents 



