CH.VP. s.] BEST SORT OP TRAVELLING COMPASS. 295 



look at it, SO long a time elapses before it settles that 

 the animal becomes fidgetty and distm-bs the needle 

 again. By far the best pocket-compass to have, is 

 one that has a glass bottom as well as a glass top to 

 it, like those which are commonly hung up in the 

 cabins of ships, only, of course very much smaller, 

 say one inch across. The pivot on which the needle 

 turns is fixed in a hole drilled through the bottom 

 glass. Concentric vdth the needle, and turning stiffly 

 round its cap, is a small piece of brass, shaped, say, 

 like a fish, so that its head could never, even by the 

 faintest light, be mistaken for its tail. The top glass 

 of the compass should unscrew. 



Before starting, having determined in which direc- 

 tion you intend to proceed, take off the top glass and 

 adjust the head of the fish so that it shall point in 

 that direction; there is now no chance of error or 

 confusion ; you forget all about the needle and only 

 think of the fish. When it becomes dark, you have 

 simply to hold up the compass between your eye and 

 the sky, and the fish can be seen quite plainly ; but 

 an ordinary compass can never be deciphered after 

 dusk. If any doubt remains, the light of a cigar or 

 a piece of white paper held below the compass will, 

 when you look down upon it, bring out the fish quite 

 clear and distinct. It is much better to hang the 

 compass by three threads, like a scale-pan, than simply 

 to hold it in the hands ; the threads take the place of 

 gimbals, and, besides, being more compact in the 

 pocket, are also less likely to get out of order. For 

 a pocket-compass, no great accuracy is required ; if the 



