Barometer. 



liii 



Table 10. — Comparisons of the Makerstoun Standard Barometer with the 

 Barometer Troughton " B," July 8d— 10^ 1847. 



Makerstoun Standard. 



Troughton " B." 



Troughton "B" 



minus 



Makerstoun 



Standard. 



Height. 



Tempera- 

 ture. 



Height. 



Tempera- 

 ture. 



Corrected to 

 Temp, of 



Makerstoun 

 Standard. 



in. 



29-722 

 29-717 

 29-924 

 30-061 

 29-987 



68-7 

 66-4 

 71-3 

 61-5 

 67-0 



in. 



29-682 

 29-667 

 29-882 

 30-020 

 29-946 



73-0 

 66-8 

 74-9 

 65-2 

 71-3 



29°67l 

 29-666 

 29-873 

 30-010 

 29-935 



in. 



-0-051 

 •051 

 •051 

 •051 

 •052 

 1 



From these comparisons we find 



in. 



Troughton B minus Royal Society's flint-glass, ....=— 0-0417 

 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 Argyle's, . . . = -f 0-0029 



Makerstoun standard barometer minus Royal Society's flint-glass, . = + 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— "012 inch to the mean of the Boyal 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 

 h h are 0*3 inch in diameter, and tenths of a degree can be estimated with accuracy 

 on the scales a a ; the thermometers are attached to a wooden slab c, fixed to the 



MAG. AND MET. OBS. 1845 AND 1846. 



