[ 396 ] 
N° XLV. 
Extract of a Letter from BERNARD Romans, of Pen/a- 
cola, dated Auguft 20, 17740 
HE common mariners compafs has always appeared 
T to accurate obfervers as an imperfect inftrument, but 
in nothing has it proved to be more defective than in its 
ufe in ftorms, the heavieft brafs compaffes now in ufe are 
by no means to be relied on in a hollow or high fea. 
This is owing to the box hanging in two brafs rings con- 
fining it to only two motions, both vertical, and at right 
angles with each other, by which confinement of the box 
upon any fuccuffion, more efpecially fudden ones, the card 
is always put into too much agitation, and before it can 
well recover itfelf, another jerk again prevents its pointing 
to the pole, nor is it an extraordinary thing to fee the card 
unfhipped by the violence of the fhip’s pitching. 
All thefe inconveniencies are remedied to the full by 
giving the box a vertical motion at every degree and mi- 
nute of the circle, and to compound thefe motions with a 
horizontal one, of the box, as well as of the card. By this 
unconfined difpofition of the box the effeéts of the jerks 
on the card are avoided, and it will always very fteadily 
point to the pole. Experience has taught me, that the 
card not only is not in the fmalleft degree affected by the 
hollow fea, but even in all the violent fhocks and whirl- 
ings the box can receive, the card lies as {till as if ina 
room unaffected by the leaft motion. 
Lately a compafs was invented and made in Holland, 
which has all thefe motions. It is of the fize of the com- 
mon brafs compaffes, the bottom of the hrafs box inftead 
of being like a bowl, muft be raifed into a hollow cone, 
like 
