OF THE CEITICAL VELOCITY OF AVATER WITH TEMPERATURE. 
Table II.— continued. 
5U 
( 
Number of 
experiment. 
Temperature, 
“ C. 
Time, 
seconds. 
Total weight 
of Avater 
discharged, 
pounds. 
Difference of 
head in 
centimetres of 
mercury. 
log r, 
V ill feet per 
second. 
h: in feet of 
Avater. 
! 107 
35-0 
23-05 
11-898 
17-415 
1 - 0285 
-8888 
j 108 
35-0 
22-52 
11-611 
17-397 
1-0277 
-8884 
109 
35 ■ 0 
27-90 
11-854 
12-703 
-9440 
-7518 
110 
35-0 
42-00 
13-0.34 
7-213 
-8075 
-5060 
111 
35-0 
54 - 95 
12-508 
4-231 
-6725 
-2743 
112 
34 ■ 9 
73-40 
12-527 
2-541 
- 5475 
-0529 
113 
34-9 
26-10 
13-370 
17-220 
1-0252 
-8839 
114 
40-4 
23-57 
12-311 
17-482 
1-0343 
-8905 
115 
39-6 
25-60 
10-905 
11-792 
- 9458 
-7195 
116 
39-2 
40-50 
11-869 
6-526 
- 7834 
-4624 
11 / 
38 ■ 8 
56 - 55 
12-214 
3-770 
- 6508 
-2241 
118 
38 • 5 
77-14 
12-308 
2 - 228 
-5191 
1-9957 
119 
38-0 
24-67 
12-802 
17-550 
1-0313 
-8920 
120 
50-5 
24-76 
12-531 
15-820 
1-0226 
-8470 
121 
50-5 
67-20 
12-771 
2-933 
-5972 
•1151 
122 
50-0 
27-18 
12-245 
12-708 
-9721 
-7519 
123 
50-0 
56-48 
11-870 
3-340 
-6410 
-1716 
124 
50-0 
32-40 
12-928 
10-44)2 
-9194 
-6686 
125 
49-8 
78-40 
12-346 
2-147 
-5178 
1-9796 
The slopes of the lines for the cliftereiit temperatures ai-e shown in the accompanying 
table, and their mean value is n= lYSl. 
Temperature, ° C. 
4-0 
10-8 
21 -2 
30-4 
35-0 
39-0 
50-0 
11 . 
1-722 
1-733 
1-740 
1-734 
1-738 
1-737 
1-715 
The dilferent values obtained are no doidjt due to temperature errors, and this view 
is confiimed vdien it is seen that tlxe variations Irom the mean value are greater the 
fill ther the temperature of the water is from the temperature of the laboratory. 
As there seems no reason to sujipose that the value of n varies with the temperature, 
the logarithmic homologues have been dravm at a mean inclination of tan~i 1731 in 
determining the critical velocity. The corrections to be applied for differences of 
temperature are now miicli smaller, and for the mean value of n = 1731 is found to 
be -0076 for a difference of 1° from a temperature of 10° C., and ’0047 for the same 
difference at 50° C. The observations for each series of runs in Table II. have been 
plotted to a mean temperature like those for stream-line motion, the temperatures 
corresponding to the interpolated homologues for stream-line motion described aliove. 
I 2 
