298 
MEASUREMENT OF HIGH TEMPER ATtTRES. 
[bull. 54. 
For the given value of (9=4° the values of the tan cp decrease about 
as rapidly as the square of B. It is to be noticed, however, that thei; 
tan cp in the case of Table 96 is probably zero, since the observed posi- 
tive tan cp in Table 104 is compensated by an observed negative tan cp 
in other similar cases. Hence if tan cp is to be represented in its de- 
pendence both on if or 6 and B, it will be necessary to assume an] 
exponential form in which powers of both B and //' are exponents. 
Supplementary results. — To further elucidate the relations under dis- 
cussion I made a series of miscellaneous low-temperature experiments.' 
Table 105 contains data for a glass tube of fine but not rigorously uniform 
capillary bore. Here the variations of 7; with P—p are quite insignificant, 
proving that the obliquity cp observed is not due to any imperfection of 
apparatus. The second part of the table contains results for a tube ofj 
larger bore than any of the metallic tubes. Nevertheless the variation 
of cp here is not proportionately large. The temperature of the re-' 
ceiver B, Fig. 44, is given under t. 
Table 105. — Transpiration in glass tubes. 
[Capillary tube No. I. L-=3Q.0«°. E=0.0111 cm . F=565.7 CC . 0=6.6°. J 
p 
V 
t" 
P 2 -P 2 „, 
p **" 
ti 
T 
*• 
124.06 
76.70 
394 
49040 
6.6 
21.0 
0. 0001505 
123. 96 
76.70 
398 
49350 
6.6 
20.8 
1515 
88.91 
76.63 
1847 
49220 
6.6 
21.2 
1511 
88.93 
76.63 
1838 
49080 
6.6 
21.4 
1508 
124. 08 
76.50 
394 
49430 
6.6 
21.6 
1517 
124. 06 
76.50 
394 
49410 
' 6.6 
21.8 
1518 
[CapillarytubeNo.il. i=34.25 cm . i?=0.0302 <:m . "r=565.7 cm . 0=6.6°.] 
86. 96 
76.48 
72 
1613 
6.6 
21.7 
0. 0001946 
86.89 
76.48 
73 
1624 
6.6 
22.3 
1960 
85.66 
76.48 
82 
1597 
6.0 
22.5 
1933 
85.72 
76.48 
82 
1598 
6.6 
22.7 
1935 
Table 106 shows that similar variations of ?/ with P—p (i. e., the ob- 
liquity cp) occurs in case of silver tubes, the capillary being employed 
in two different lengths. Curiously enough, the value of cp here does 
not vary with L. There may, however, be a compensation in B. Silver 
capillary tubes could not be obtained in such excellent quality as the 
platinum tubes. 
(952) 
