of the Barometer near Edinburgh. 155 



out, in all probability considerably too small *. On my return to 

 Scotland in autumn of the same year, I resolved to institute 

 immediately a series of observations in Latitude 56, a more 

 northerly station than any at which observations have, as far as I 

 know, yet been made for this purpose, excepting those of Cap- 

 tain Sir EDWARD PARRY. These I have pursued almost without 

 intermission, up to the close of 1830 ; and when it is recollected 

 how rare observations, sufficiently long continued, have been in 

 the higher latitudes, and especially how trivial have been the 

 donations of Great Britain to this branch of meteorology, I hope 

 that, with all the defects inseparable from the efforts of a solitary 

 observer, the results of this inquiry, placed in the form of Tables 

 at the end of this paper, and the deductions from which I am now 

 about to give in words, may not be unacceptable to the Society. 

 4. These observations, amounting in all to 4410 in number, 

 comprised between the years 187 and 1830, were made at 

 Colinton House, four "miles south-west of Edinburgh, in Lati- 

 tude 55 55' 20" N., and Longitude 12 m 57 8 .5 west of Greenwich, 

 deduced trigonometrically from the Calton Hill Observatory, 

 and at 410.5 feet above the mean level of the sea, determined 

 by accurate levelling. Four months observations, however, at 

 the commencement of 1 828, were made in Edinburgh, but re- 

 duced to the same level of 410.5 feet, in order to prevent their 

 affecting the mean absolute height. Five observations were 

 made daily of the barometer and attached thermometer, from 

 8 to 8 A. M., at 10 A. M., about 4 p. M., and at 8 and 10 p. M. ; in 

 order to detect the morning and evening maximum, and after- 

 noon minimum. The same instrument has not been used 

 throughout these observations. For the greater part of the last 

 two years, however, I have used a barometer in which I put great 

 confidence, the mercury having been boiled in the tube by my- 



* A full account of these observations was published in the Edinburgh Journal 

 of Science for January and April 1828. 



