368 Astronomical and Magnelical Observations. [May, 



variation of the compass in that part of the world. That a compa- 

 rison may be made of the present variation with that in the year 

 1790, 1 have inserted Capt. Brown's observations, on whose accu- 

 racy dependance may be placed. His journals are in my possession. 

 He commanded the ship Butterworth ; and was furnished with an 

 accurate azimuth compass, made by Mr. DoUand for the purpose of 

 maliing the observations now inserted. 



Captain Brown's Observations. 





2 



c 

 c 



I am not acquainted with tlie alteration in the v.'.riation which has 

 taken place on the Continent. From several ob-^crvations I made 

 in the year 1787} at La Rochette, near Ncuchatel, in Switzerland, 

 the variation was 19° 7' 14" VV. The latitude of this place, from 

 many observations, is 47° 00' 15" N. ; and the longitude, deduced 

 during ray residence th^^e from solar eclipses and occultations of 

 the stars by the moon, 28' 40" E. in time, or 7° 10' 00" in Space, 

 of Greenwich. 



Not being aware that any observations have been made to deter- 

 mine the situation of the supposed highest mountain in Europe, I 

 take the liberty of sending you the latitude of Monte Blanc, from 

 an observation I made under very favourable circumstances, on its 

 summit, in the month of August, 17S7 ; the latitude, deduced 

 from the meridional altitude of the sun, is 45° 49' 59 

 the summit bears from Neuchatel by the compass S. 20° 54' O; 

 by using the difterence of latitude and the true bearing, the longi- 

 tude in space is 3' 10" W. of Neuchatel, and consequently 

 7° 6' 50" E. from Greenwich. The lake of Neuchatel I found to 

 be 1428 feet above the English Channel. 



I remain, my dear Sir, yours very sincerely, 



Mauk Bkaufoy. 



" N. ; and as 



