on the Formula for measuring Heights by the Barometer. 237 
Barometric Observations on Heights near Edinburgh? and is 
intended to ascertain the height of Arthur Seat above the Pier 
head of Leith, the difference of elevation having been found, by 
levelling, to be 803 feet. 
Bar. Att. Therm. Det. Therm. 
Leith Pier, - 39.567 55 \ 54 
Top of Arthur Seat, 28.704 51 § 504 
Here the actual humidity of the air is still wanting; but it 
being mentioned that, at the time of the observations, the wind 
was SW. with rain, it cannot be far from the truth to suppose 
the point of deposition to have been 3° below the temperature 
of the air, at the lowest station, and 1J° below it, at the upper 
one. We shall thus have f— *390 and f f — '364. The seve- 
ral corrected coefficients are as subjoined : 
1. Correction for the temperature of the air. 
I — 32 j = 1 + -002086 x 20.25 = 1-04224. 
2. Correction to reduce the two mercurial columns to the same 
temperature. 
28-704 (1 + 000103.55 j — 51 1) = 28-704 (1 + -00036) =28-714. 
1 + 002088 ff 
3. Correction for the dilatation of the aerial column by va- 
pour. 
_ -390 + -364 1 , 754 1012107 
+ 29-567 + 28-714 — (-390 + -364) ” 1 + 57.527 ~ 
4. Correction for the pressure of atmospherical vapour. 
*390 
\f= 29-567 
6 
•364 
= 29-567 — -065 = 29.502. 
H — \f = 28-714 — ^ - 28-714 — 061 = 28-653. 
A " d ^ 131 = - 012680 . 
Hence h — 10,000 x 1 04224 x 1 013107 x -01268 = 133-88 
fathoms, = 803*28 feet. This result differs only about 3 inches 
from the height, as it was determined by levelling, — a coinci- 
dence which is, no doubt, partly accidental, as it is considerably 
within the limits of the exactness furnished by the data, which 
would admit, a deviation of at least 5 feet, when all the observa- 
tions are taken with the utmost care. 
VOL. XIII. NO. 26. OCTOBER 1825. 
R 
