Mr f de Luc on 
comparatively to that of their refpedtive flips •, and thus are 
completed their hygrofcopic pales . Repeated trials have fhewn 
me, that the weight of the pavings increafes as long as their 
flips increafe in length ; but as there is no regularity in their 
comparative marches at that period of moijlure in a vefiel, nor any 
poffibility of making thefe experiments in open air, becaufe of 
the beams ; the addition mentioned, which forms the three laft 
terms of the columns of the pavings in the following table, is 
to be confidered only as having determined the modulum of the 
cbferved terms ; fince it has not changed the ratio between them, 
nor confequently the correfpondent marches of weight and 
length fo far ; which were the only objeft of the experiment. 
50. Before I come to the general refult of that experiment, 
I (hall place here a comparative view of the two kinds of phe- 
nomena, which, by their analogy, led me firft to the theory I 
have expofed : I mean the comparative marches of the flip and 
thread of whalebone on one fide, and thofe of th 0 thermopopes 
of quickfilver and water on the other fide. In this table the 
correfpondent terms of the hygropopes, from o of both to 85 of 
the flip, have been obferved in the above experiment; the four 
following are the refults of obfervations in time of increafing 
dew. The correfpondent terms of the thermopopes are deduced 
from the table of their comparative expanfions which I have 
given in § 418. m. of my work, Rech. fur les Mod. de /’ Atmo* 
Jphere ; from which table this only differs, ift, by a change 
of the modulum , in the ratio of 80 to 100; 2d, by an inver- 
fion , which brings the terms of this table to exprefs compara- 
tive condenfations of the two liquids. 
Hygro- 
