at Sierra Leone, by Captain Sabine. 6*9 



due to these differences being corrected for the latter circum- 

 stances, in the manner and agreeably to the tables which you 

 have given in the XXVth Number of the Quarterly Journal of 

 the Royal Institution, it results that the floor of the gallery of 

 the clergyman's house at Regent- town is 983.6 feet, and the 

 summit of the Sugar-loaf, 2521.6 feet above the sea. 



I have taken the liberty to add (though without permission) an 

 extract of a letter which I have received, since my return to Eng- 

 land, from Thomas Stuart Buckle, Esq., engineer and surveyor 

 of the colony, stating the result of a comparative geometrical 

 measurement. " I was much gratified to find, on computing the 

 altitude of the Sugar-loaf, from the trigonometrical observations 

 that I had taken, that the result differs from your barometrical 

 measurement only a few feet; I make its height 2493 feet : the 

 height of Leicester Mountain I computed to be 1954, and it 

 was sufficiently satisfactory, on taking into account the dis- 

 tance of the Sugar-loaf from Leicester Mountain, and the ex- 

 cess of its height above that of Leicester Mountain, that the 

 result of the latter was 537 feet, which, added to 1954, amounts 

 to 2491, differing from the former calculation only two feet." 



I have added the barometric measurements of well-known 

 places in the islands of Ascension, Trinidad, and Jamaica ; but I 

 am not aware of any previous results with which to compare them. 



Height of the Mountain-house at Ascension. — July 9th, 1822, 

 at 9^ 30'" A.M., a barometer, 17 feet above the sea, in a room 

 in the Barrack-square at Ascension, stood at 30.165 in., the 

 temperature of the air and mercury being 83°, and of the point 

 of deposition 68°; whilst, at the same time, another barometer 

 three feet above the floor of the Mountain-house, stood at 

 27.950 in., the air and mercury 70.3, and the point of deposi- 

 tion 66.5. From these data, the floor of the Mountain-house 

 would appear 2221.8 feet above the sea. 



The upper barometer was then taken to the summit of the 

 island, but the registry at that height has been mislaid; it was 

 27.3 and some hundreds, being less than 70Q feet above the 

 Mountain-house ; consequently, the highest part of Ascension 



