490 



ACCOUNT OF 



the largest ships. On the passage home I also 

 found it very correct in the indication of the winds 

 and weather." 



An opportunity of trying the Sympiesometer in 

 a very different climate ocurred last year, when the 

 Expedition under Captain Ross sailed to the Arc- 

 tic Regions. Lieutenant Robertson of the Isabel- 

 la kindly undertook the charge of this instrument, 

 and regular observations were made every four 

 hours with the Sympiesometer and Marine Baro- 

 meter, the results of which were highly satisfactory. 

 The observation scommenced on the 24th of April, 

 in North latitude 51° 39' and longitude 1° f E. ; and 

 were continued to the latitude of 76° 50' N., and du- 

 ring the return of the Expedition to Deptford till 

 the 13th of November. These observations, in the 

 form of a graphical representation of the progress of 

 the Sympiesometer and Marine Barometer, have 

 been published in Captain Ross's Account of the 

 expedition, and will enable navigators to form a cor- 

 rect estimate of the relative value of the two in- 

 struments. 



The following is Captain Ross's official report up- 

 on the Sympiesometer: 



" This instrument acts as a marine barometer, 

 and is certainly not inferior in its powers. It has 

 also the advantages of not being affected by the 

 ship's motion, and of taking up very little room in 

 the cabin. I am of opinion, that the instrument 



