FREDERICK GUTHRIE OH THE THERMAL RESISTANCE OE LIQUIDS. 651 
T =21-22 
T 1= 31-22 
AT =10 
& = 0 . 
AH, which has to be found, represents the corrected depression in millimetres. 
t x =\ min. 
t,— 2 min. 
£=3 min. 
t. 
AH,. 
AH,. 
ah 3 . 
s 
millims. 
millims. 
millims. 
0 
111-65 
119-56 
123-06 
0 
103-76 
119-12 
123-06 
0 
106-17 
118-71 
122-84 
0 
105-18 
118-99 
123-00 
0 
106-17 
119-42 
123-17 
0 
105-69 
119-35 
123-06 
Mean . 
. 106-44 
119-19 
123-03 
In another experiment, where t x = 1 min. throughout, AT was taken as 10°, 20°, and 
30° C. in succession. 
o 
T = 
T x = 
t 2 = 
t 3 = 
20-17 
30-17 
: 40-17 
:50-17. 
q=l min. 
A 
t. 
AT =10°. 
AT =20°. 
AT=30<\ 
s 
millims. 
millims. 
millims. 
0 
106-17 
235-47 
414-48 
0 
105-86 
233-83 
422-49 
0 
106-17 
234-29 
421-24 
AH=106-07 
234-53 
419-40 
We can employ these correctionary data to the numbers subsequently obtained when 
liquids intervene, without previously reducing the linear depression to cubic propor- 
tional expansion. 
§ 51. Relation between resistance and thickness . — We have already obtained some 
notion of this relation in examining the time t required for heat to traverse different 
thicknesses of water. Taking the same liquid, we may now estimate the resistance by 
finding how much heat passes through in a given time, and therefore how much is 
arrested. The resistance is considered as the number of heat-units (1 grm. 1° C.) which 
the liquid arrests in a given time ; but for our present purpose we need not make the 
latter reduction ; the corrected linear depression in millimetres will suffice. 
T =19-28 
T x =29-28 
AT =10 C. 
fj = l min. 
