204, & r ° Marcet on the specific gravity and temperature 
Table IX. Representing the Temperature at the Surface in a series 
of latitudes , both going out and coming home ;* such as observed 
by Mr. Fisher. 
* Each of these results is a mean between all those taken between each degree of 
latitude and the succeeding one ; thus the temperatures annexed to 65 °, which are 
44.9° and 42-7°, are means between the observations taken between 65 ° and 66 °. 
The specific gravities are means of those taken both going out and coming home ; 
for the differences of specific gravity (which, when the ship was in motion, was ob- 
served by an Hydrometer, by Troughton) were probably in a great degree occa- 
sioned by the unavoidable errors of observation, 
