452 



Prof, J. Perry on Liquid Friction. 



Table V.— March 21st, 1892. {I— 6*075 centiin.) 



e°c. 



22-5 



n. 

 9-25 



D. 



y> 



* 



24-5 



3-40 



•283 



23-2 



11 



28-0 



3-97 



•278 



22-7 



14-2 



37 



5-16 



•280 



22-0 



172 



45 



615 



•279 



25-0 



27 



68 



10-19 



•277 



245 



23 



57 



8-41 



•281 



24-0 



32 



77 



11-20 



•269 



23-0 



90 



340 



48-00 





22-5 



102 



410 



56-96 





23-0 



80 



276 



3894 





240 



72 



224 



32-58 





24-5 



56 



169 



24-95 





24-0 



48 



129 



18-76 





23-5 



43 



108 



15 42 



•278 



23-0 



38 



• 97 



13-69 



•277 



The column headed y is D/(Z + X) corrected to the constant 

 temperature of 24° C. by a correction of about 3 per cent, per 

 degree. The numbers in the last column have no meaning 

 for speeds higher than n= about 43. The average value of /x, 

 the viscosity, in the first seven and last two observations is 

 0-278. Formula (9) would make (jl for this temperature 

 0-266. 



Plotting log n and logy on squared paper gives points 

 lying nearly in two straight lines, showing that y oc n to the 

 critical speed n — about 43, and above that speed y ocn 1 ' 31 . 



Table VI.— March 21st, 1892. (1= 6'075 centim.) 



e°c. 



n. 



D. 



_± 



11-63 



29'5 



38 



81 



30 



43 



95 



13-82 



31 



48 



114 



16-99 



30-5 



56 



134 



19-73 



30-5 



60 



147 



21:65 



30 



66 



175 



25-45 



y here means D/(l + \) corrected to the constant temperature 

 of 30° C. by a correction of 2^ per cent, per degree, ^ as 

 calculated from (7) would have no meaning, as the critical 

 speed for this temperature is about 28 revolutions per minute, 

 and we give no column headed ja. y is very nearly an 1 ' 33 . 



