( ipi ) 
III. Account of an Experiment^ made to afcer-- 
tain the proportion of the Expansion of the Li- 
quor in the Thermometer^ with Regard to the De- 
grees of Heat, Dy Brook Taylor, LL.D, 
T(,S.S. 
I T has, I believe, been generally fuppofed, tho’ not 
proved, that the Expanfion of the Liquor in the 
Thermometer, is proportional to the Increafe of Heat, 
To determine this Matter with Certainty, I made the 
following Experiment. 
I provided a good Linfeed Oil Thermometer, which 
I marked with fmall Divihons, not equal in Length, 
but equal according to the Capacity of the Tube in the 
feveral Parts of it, as all Thermometers ought to be 
graduated, f likewife provided two VelTels of thim 
Tin, of the fame Shape, and equal in Capacity, contain- 
ing each about a Gallon. Then (obferving in every 
Trial, that tile Veifels' were cold, before the Water was 
put in them, as alfo that the VefTell meafured the hot 
Water with, was well heated with it) I fucceflively 
fill’d the Vefiels with one, two, three, &c. Parts of 
hot boiling Water, and the reft cold ^ and at laft with 
all the Water boiling hot^ and in every Cafe I iminer- 
fed the Thermometer into the Water, and' obferved^to 
what Mark it rofe, making each Trial* in both' VelTels 
for the greater Accuracy. And having; firft obferved 
where the Thermometer ftood in cold Water, I found 
that its rifing from that Mark, or the Expanfiomof the 
Oil,, was accurately proportional to theCiiiantity ofhot 
Water in the Mixture, tliat is, to the Degree of Heat. 
I IV, An 
