App. 11. REMARKS ON INSTRUMENTS. 463 



BemarJcs on (lie Instruments used in taking the Astronomical 



Observations. 



No. 1 Sextant, 4 inches radius, by Caiy, was used for the altitude 



of the stars and planets in connection with a lunar. 

 No. 2 Sextant, 6 inches radius, by Gary (the best instrument), 



always used for time, and in taking the distance in a lunar 



and meridian altitude. 

 No. 3 Sextant, used for altitude of the moon under 120° (art. 



hoiiz.), and when more than that quantity one of the other 



sextants was used. 



All the above were lost in my retreat, except the watches and 

 two aneroids. 



All the instruments above enumerated were carefully tested 

 before leaving England. The aneroids brought back were 

 again tested after my arrival. 



My watches proved to have kept very good time ; and I ought 

 to express here my thanks to Mr. Brock, of George Street, 

 Portman Square, for the care he took in supplying me with 

 the best watches. They are still in good order ; and I am 

 greatly indebted to Sir George Back for recommending Mr. 

 Brock to me. The instruments by Mr. Potter, successor of 

 Mr. Gary, of 181, Strand, proved to be excellent, and stood 

 well the rough travelling they had to go through. 



