[ 102 ] 
of buoyancy was principally owing to the warmth 
the water had got by handing in a warm room, as 
was hinted at before, which was further proved by the 
thermometer ? 
Two other floats, of 44 grains of cork each, having 
been 72 hours in river water, weighed each 53 grains, 
having gained nine grains by the immcrfion. Being 
laid to dry for 24 hours after, weighed 46 grains, 
having relinquifhed feven grains each. 
The float C, being wiped and put into a dry place 
for 24 hours, W'as found to weigh 183 grains, having 
gained 19 grains of weight. The float, in this 
hate, was thenimmeiTed in fait water, and was found 
to fupport 864 grains, being 1 10 grains more than 
it fupportcd in frefli water, after it had been faturated 
therewith} C, being left in fait water 48 hours, was, 
upon weighing, found to have loft fix grains of its 
buoyant power. This float C, having been 72 hours 
immerfed in the fea water, was found, after being 
well wiped, to weigh 203 grains, having increafed 
in weight 20 grains by immerfion. After being nine 
hours out of the fait water it was found to weigh 
188 grains, having loft in that time 15 grains. 
Experiment VIII. 
A medal of lead, weighing one drachm when out 
of the water, was found, on being weighed in river 
water, to be 54 grains and a half} being lefs by five 
grains and a half than out of the water. The fame 
medal being weighed in the fait w^ater was found 
to weigh 53 grains and a half. The difference between 
its hydroftatical weights being precifely one grain, or 
more in river water than in fea water. 
Expe- 
