IMPROVEMENT or THE COMPASS. 397 
like the bottom of a common glafs bottle; the vertex of 
the cone muft be raifed fo high as to leave but one inch 
between the card and the glafs; the box mutt be of the 
ordinary depth, and a quantity of lead muft be poured in 
the bottom of the box round the bafe of the cone, this fe- 
cures it on the ftyle whereon it traverfes. 
This flyle is firmly fixed in the center of a fquare wood- 
en box, like the common compafs, except that it requires 
a thicker bottom. The ftyle muft be of brafs about fix 
inches long, round and of the thicknefs of one-third of 
an inch, its head blunt, like the head of a fewing thimble 
but of a good polifh; the ftyle muft ftand perpendicular, 
the inner vertex of the cone mutt alfo be well polifhed ; 
the vertical part of the cone ought to be thick enough to 
admit of a well polifhed cavity fuflicient to admit a fhort 
ftyle proceeding from the center of the card whereon it 
traverfes. The compafs I faw was fo conftructed, but I 
fee no reafon why the ftyle might not proceed from the 
center of the vertex of the cone, and fo be received by the 
card the common way. The needle muft be a magnetic 
bar blunt at each end; the glafs and cover is put on in 
the common way. 
A compafs of this kind was given by the captain of a 
Dutch’ man of war to Capt. Burnaby of the Zephyr floop ; 
this gentleman gave it to me to exarnine, and was very 
profufe in his encomiums thereon, faying that in a very 
hard gale, which lafted fome days, there was not a com- 
pafs but it of any fervice at all. Indeed to me it appears 
to deferve all the praife he gave it. My ftay is fo fhort 
here, as not to allow me time to have one made; but I 
intend to have one made for my own ufe, and fhall offer 
it to the fociety for infpection. I hope that this ufeful 
inftrument may become univerfal, as navigation certainly 
will be rendered more fafe through its means ; and I fhall 
think myfelf highly honoured, if through the channel of 
this fociety it becomes public. 
Breve Prefents 
