1858.] 



On Uypsometrical Measurements. 



337 



8th April. — At noon latitude 7° 34' N. longitude 89° 1' E. winds 

 S. W., steady breeze and fine. 



9th April— At noon latitude 8° 28' N. longitude 90° 52' E. winds 

 S. W. and W. S. W., fresh breeze and cloudy. 



10th April— At noon latitude 10° 23' JST. longitude 92° 40' E. 

 sighted little Andaman at 8 a. m., wind N. W. all day, fine and 

 steady. 



Memo, of observations at Chatham Island, Port Blair, 

 Barometer. By Br. Gamumer. 



7th April 



Bar. Wind. 

 Sunrise. — 29.82, Easterly. 

 10 a. m.— 29.82, N. E. 

 4 p. m.— 29.82, N. E. 

 Sunset.— 29.80, E. N. E. 



8th April 

 Bar. Wind. 

 29.77, South. 

 29.79, S. 

 29.77, S. 

 29.77, S. W. 



9th April 

 Bar. Wind. 

 29.73, S. W. 

 29.83, S. W. 

 29.83, W. 

 29 .85, N. W. 



10 th April. 

 Bar. Wind. 

 29.86, W. 

 29.88, W. 

 29 92, W. 

 29.92, N.W. 



Remarks. — It commenced to blow head at midnight, following 

 the 7th. The position of Chatham Island being confined within the 

 harbour, the indications will not follow the smaller changes in the 

 open sea, but for the greater alterations in the directions of the 

 wind, they are sufficiently close. 



On Uypsometrical Measurements by means of the Barometer, and 

 the Boiling-point Thermometer. — By James Burgess, Esq. 



The whole subject of the barometrical measurement of heights 

 has been investigated by so many eminent physicists since the 

 time of Pascal and Descartes, that it is not to be expected that 

 much that is new can now be added to the theory. The object 

 of this paper is — (1) by correcting the constants used in the latest 

 development of the usual formula, according to the most recent 

 and trustworthy experiments, to render the results obtained in 

 practice as accurate as possible ; and, — (2) to deduce formula) and 

 tables for facilitating the computation of heights by means of the 

 temperature of boiliug water, which shall give results more in 

 accordauce with the truth than the tables hitherto employed. 



