INTEODUCTION. 



DESCRIPTIONS OF INSTRUMENTS, ADJUSTMENTS, AND DATA 



FOR REDUCTIONS. 



§ 1. Position and Description of the Observatoey. 



1. The Magnetical and Meteorological Observatory at Makerstoun, in Rox- 

 burghshire, was erected by General Sir Thomas Makdougall Brisbane, Bart., in 

 the year 1841. The geographical co-ordinates are as follow : — 



Latitude, . . . . 55° 34' 45" N.* 



Longitude, . . . . O'' 10™ B-5^ W. of Greenwich.! 



Height of the barometer cistern above mean water at Berwick, 213 feet. 



The last ordinate was obtained by connecting the Astronomical Observatory 

 with levels made from Berwick to the opposite bank of the Tweed, for a railway 

 from Berwick to Melrose. This determination has been verified by the results of 

 many series of barometrical observations, made simultaneously at Berwick and 

 Holy Island by Sir T. M. Brisbane, and at Makerstoun by Miss M. Brisbane. 

 The following are examples of the results taken at random : — 



Height of the cistern of the barometer in Sir T. M. Brisbane's library above 

 mean water at 



Feet. 



Berwick, Aug. 21, 22 1837, 10 Comparisons, . . 221-6 



Holy Island, Oct. 9, —4 p.m. 1839, 1 



Oct. 10, 16—9 a.m. ... 6 



— Noon, ... 6 



— 3 P.M. ... 4 



... 2 



226-2 

 229-7 

 227-1 

 229-3 

 220-9 



Feet. 



Giving the results weights depending on the number of comparisons, the mean is 225-6 

 The correction to the Observatory barometer cistern (by levels) . . . - 12-0 



Height of Observatory cistern, 213-6 



* Ast. Nach., vol. x. p. 214. f Mem. Ast. Soc, vol. xi. p. 171. 



MAG. AND MET. OBS. 1843. C 



