314. J. LeConte—Horizontal Motions of Floating Bodies. 
tions, instead of being as 1 to 2, as the theory demands, is more 
nearly as 1 to z,,as pointed out by Simon. 
3. The numbers in the columns of T and 'T’ show that if the 
ngle of contact remains the same, the computed values of the 
paren tensions in the cases of tubes and parallel plates, are 
not constant under variations of d and d’ respectively ; in fact, 
they do not even approach constancy until ¢ and d’ become 
respectively less than 0-2 of a centimeter. On the contrary, 
and ‘I’ respectively augment with the diminu- 
tion of dand d’. Thus, a change in the value of d from 18 to 
1-4 centimeters increases T in the ratio of 100 to 171; and a 
similar change in d’ augments the value of T’ in the ratio of 
62 to 109. pret a change in the value of d’ from 1°0 to 06 
centimeters, increases T’ from O-OL88 to 0-0846 grams per cen- 
timeter o 
4. The same walatned show, that instead of T being equal to 
T’ (as required by theory), the former, under the same values 
of d and a’, always exceeds the latter in nearly the ratio of 16 
to 1, or toh 
come compaintively large as their proximity y seen 
other terms, we have seen that the value of the surface- ate 
instead of being constant under all conditions, as the theory of 
capillarity assumes, is, in reality, an inverse function of the 
radius of curvature of the meniscus; so that the elastic pare < 
tion of the tense liquid film acts uneque ally on the oppos att 
sides of the floating bodies, and thus becomes the true physic” — 
cause of their motions. ie 
Thus far I have considered the phenomena in question a8 — 
due exclusively to the change in the surface-tension incident wi : 
the proximity of the floating solids; but it is evident that & 
* # The value of the assumed “ capillary constant,” T, for water given by Quineke _ 
0°08253 grams per centimeter of contour, evidently ¢ corresponds to its phe o 
glass tube whose internal diameter is about 0°15 of a centimeter. In the 0. 
system this is equivalent to 008253 x g=80°96 : 
+ This Journal, III, vol. xxiv, p. 421, December, 1882. 
