BAROMETER. hii 
TABLE 10.—Comparisons of the Makerstoun Standard Barometer with the 
Barometer TROUGHTON “ B,” July 84—10*, 1847. 
Makerstoun Standard. Troughton “ B.” 
Troughton “B” 
minus 
Corrected to Makerstoun 
. Tempera- Tempera- Temp. of B 
Height. ture. Height. ture. Makerstoun Sine wis 
Standard. 
in. : in. = in. in. 
29-722 68-7 | 29-682 73-0 29-671 | —0-051 
29-717 66-4 29-667 66-8 29-666 ‘051 
29-924 71-3 | 29-882 74-9 29-873 | -051 
30-061 61:5 30-020 65-2 30-010 -051 
29-987 67-0 29-946 71:3 29-935 -052 
From these comparisons we find 
in 
TroventoN B minus Royal Society’s flint-glass, . . . . =— 00417 
Makerstoun standard minus Troughton B, . . . . . - =+ 0:0512 
Makerstoun standard minus Royal Society’s flint-glass, . . =+ 0-0095 
In the comparisons made in 1841, the mean of both the crown and flint glass 
tubes has been employed: making use of Tables 23 and 24, Introduction, 1841-2, 
we find 
in. 
DUKE of ARGYLE’S barometer minus Royal Society’s flint-glass, . . = + 0:0055 
Makerstoun standard barometer minus DUKE of ARGYLH’S, . - - =+ 0:0029 
Makerstoun standard barometer minus Royal Society's flint-glass, . =+ 0:0084 
‘The comparisons in 1841 and 1847, therefore, differ only one-thousandth of an 
inch. 
88. All the observations of the Makerstoun standard barometer are corrected 
by—0-012 inch to the mean of the Royal Society’s flint and crown glass barometers ; 
they are also corrected for temperature to 32° Fahr., by ScHuMACHER’S Tables, given 
in the Report of the Committee of Physics of the Royal Society of London. The 
cistern of the barometer is 213 feet above the mean level of the sea at Berwick-upon- 
Tweed. 
THERMOMETERS. 
89. The dry and wet bulb thermometers a a are by ADIE and Son. The bulbs 
bb are 0°3 inch in diameter, and tenths of a degree can be estimated with accuracy 
on the scales aa; the thermometers are attached to a wooden slab c, fixed to the 
MAG. AND MET. oBs. 1845 AND 1846. 0 
