4is} ANNUAL REGISTER, 1796. 
Account of an Improvement in Sea 
Compasses ; by Mr. B. Remansy of 
Pensacola.——F rim the Philisophical 
Transa@ions of the American Phi- 
bosophical Society. 
THE common mariner’s com. 
pass has always appeared to accu- 
sate observers as an imperfect in- 
strument, but in nothing has it 
proved to be more defective than in 
its use in storms ; the heaviest brass 
compasses now in use are by no 
means to be rebied on in 2 holiow 
or high sea, This is owing to the 
box hanging in two brass rings, 
confining it only to two motions, 
both vertical, and at right angles 
with each other; by which con- 
finement of the box, upon any 
succussion, more especially sudden 
ones, the card is always put into 
too much agitation, and, before it 
can well recover itself, another 
jerk prevents its pointing to the 
pole ; nor is it an extraordinary 
thing to see the card unshipped by 
the violence of the ship’s pitching. 
All these inconveniencies are 
remedied to the full, by giving 
the box a vertical morjon at every 
degree and minute of-the circle, 
and compounding these motions 
with a horizontal one, of the box, 
as well asof the card, By this un, 
confined disposition of the box, 
the effects of the jerks cn the card 
are avoided, and it will always 
very steadily point to the pole, 
Experience his taught me, that 
the card not only is not in the 
smallest degree affected by the 
hollow sea, but that, in all the vio- 
lent shocks and whirlings the box 
can receive, the card lies as still as 
if in a room unaffeted by the least 
“motion. 
Lately a compass was invented 
and mis 
im Holland, which:has all 
these motions. It is of the size of — 
the common brass compasses: the 
bottom of the brass box, instead of 
eing like a bowl,’ must be raised 
into a hollow cone, like the bot- 
tom of a common glass bottle: the 
vertex of the cone must be raised 
so high as to leave but one inch 
between the card and the glass} 
the box must be of the ordinary” 
depth ; and a quantity of lead must 
be poured in the bettom of the 
box, round the base of the cone 4 
this secures it on the stile whereon 
it traverses. 
This stile is firmly fixed in the 
centre of a square wooden box, 
like the common compass, except 
that it requires a thicker bottom, 
The stile must be of brass, abour 
six inches long, round, and of the 
thickness of one-third of an inch; 
its head blunr, like the head of a 
sewing.thimbie, but of a good 
polish: the stile must stand per- 
pendicular. The inner vertex of 
the cone must also be well polished; 
the vertical part of the cone 
ought to be thick enough to allow 
of a well polished cavity, suff. 
cient to admit a short stile, pro- 
ceeding from the ceatre of the card 
whereon it traverses. The com. 
pass I saw was so constructed 5 but 
J sce no reason why the stile might 
not proceed from the centre of the 
vertex of the cone, and so be re- 
ceived by the card the common 
way. ‘The needie must be a mag= 
netic bar, blunt at each end; the 
glass and cover are put on in the 
common way. 
A compass of this kind was given 
by the captain of a Dutch man of 
war to captain Barnaby of the 
Zephyr sloop ; this gentleman gave 
it tome to examine, and was very 
profuse in his encomiums thereon 
sayingt 
