298 
The Rev. F. J. H. Wollaston on the 
In the application of this table to use, it must be adapted 
to the scale of the particular thermometrical barometer em- 
ployed. In my former paper, I observed that a change of 
1° Fahrenheit appeared to be produced by 0,589 of the com- 
mon barometer. This was deduced from the comparison of 
my long thermometer of 3,98 inches to every degree with 
a common barometer. But having subsequently compared 
the same thermometer with a mountain barometer by 
Troughton, where I could ascertain the adjustment for the 
height of the mercury in the basin, I found that at a mean 
of 29,5 inches, 0,603 barometer corrected was equal to T 
of Fahrenheit. This conclusion agrees very closely with 
the table deduced from Dr. Ure’s observations, in which be- 
tween 211 0 and 212 0 , the difference of the mercurial column 
is 0,605 nearly at the mean height of 29,7, and would be 
rather less at 29,5. On the scale of the instrument which I 
have now in use, the half inch is divided into, ten parts, and 
by the Vernier into a hundred ; the inch, therefore, into two 
hundred; and I find by observation, that i,oco of the cor- 
rected barometer equals 372 parts on the scale of the ther- 
mometrical barometer, or 1,86 inch ; consequently, 0,605 
barometer or i° Fahrenheit, = 225 parts on the scale, or l-g- 
inch, which is a sensibility entirely sufficient. And those 
225 parts being supposed, according to Table I, =531 feet 
between 21 1° and 212 0 , 100 parts will equal 236 feet at that 
part of the scale. Between 202° and 203°, 225 parts = 552 
feet, and, consequently, 100 parts = 246 feet nearly ; and so 
of every other point ; and the following table of heights, 
corresponding with the scale of my instrument, will be found 
in the nearest whole numbers. 
