IMPROVEMENTS IN MARINERS' COMPASSES
Year: 1876

page_text: LETTERS PATENT to Nugent Wells, of Newport, in the County of Monmouth,
Optician, for the Invention of "IMPROVEMENTS IN MARINERS' COMPASSES."
Seeled the Oth Santamben 1876 and dated the 17th March 1876
PROVISIONAL SPECIFICATION left by the said Nugent Wells at the Office of
the Commissioners of Patents on the 17th March 1876.
NUGENT WELLS, of Newport, in the County of Monmouth, Optician.
MENTS IN MARINERS' COMPASSES."
"IMPROVE-
My Invention relates to the compasses known as liquid compasses, with the
object of permitting the compass to be used as a pole compass, or be placed at any
elevation, and be read with equal facility at the same time, from above and below,
and whether by night or day.
I propose to make the box or kettle, within which the card is placed, with a
transparent top and bottom, say of glass, the sides of the box being of metal or other
suitable material, having a lining forming a vacuum between it and the case, said
lining being of thin metal or other material which will adjust itself to the expansion
and contraction of the liquid under changes of temperature.
I propose to float the card in glycerine, or glycerine and water, spirit, or any
suitable liquid, and to carry it upon a pivot supported upon a rod passing across
the box near the bottom, and riveted or otherwise secured to the side thereof, or
supporting the card upon any suitable bearing.
I propose to make the card of talc, but may use any suitable transparent material,
and as this card is floated in a transparent medium placed between two transparent
plates, it will be evident that whether light be thrown upon it from the top or the
bottom it may be read with equal facility from above and below.
I propose to suspend the compass box in gimbals in the ordinary manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Nugent Wells in the Great Seal Patent Office on the 14th September 1876
NUGENT WELLS, of Newport, in the County of Monmouth, Optician. " IMPROVE-
MENTS IN MARINERS' COMPASSES."
My Invention relates to the compasses known as liquid compasses, with the
object of permitting the compass to be used as a pole compass, or be placed at any
elevation, and be read with equal facility at the same time, from above and below,
and whether by night or day.
I make the box or kettle, within which the card is placed, with a transparent top
and bottom, say of glass, the sides of the box being of metal or other suitable
material, having a lining forming a vacuum between it and the case, said lining
being of thin metal or other material which will adjust itself to the expansion and
contraction of the liquid under changes of temperature.
I float the card in glycerine, or glycerine and water, spirit, or any suitable liquid,
and carry it upon a pivot supported upon a rod passing across the box near the
bottom, and riveted or otherwise secured to the sides thereof, or supporting the
card upon any suitable bearing.
1 make the card of talc, but may use any suitable transparent material, and as
this card is floated in a transparent medium placed between two transparent plates,
it will be evident that whether light be thrown upon it from the top or bottom it
may be read with equal facility from above and below.
I suspend the compass box in gimbals in the ordinary manner.
On the accompanying Sheet of Drawing, forming part of this my Specification,
Figure 1 represents an elevation of a compass embodying my Invention; Figure 2
a general plan of same, when seen from the top; Figure 3 a sectional elevation
taken through the centre, and Figure 4 a sectional plan taken through the centre
of the inlet hole for the admission of the transparent liquid in which the compass
card is immersed. Similar letters of reference denote similar parts in each of the
Figures respectively.
a, a indicating the transparent plates, top and bottom. B the transparent
compass card, which is immersed in a transparent liquid contained between the two
end plates a, a¹, and the inside casing of the box c, c. d, d, outside casing forming
with the inside casing c, c, the air or vacuum chamber F, F.
Having now described and ascertained the nature of my said Invention, and in
what manner the same is or may be performed, I desire it to be understood that I
do not limit myself to the precise details of construction herein-before set forth and
illustrated on the accompanying Sheet of Drawing, as such may be varied while
retaining the essential characteristics of my Invention, and that what I claim as
secured to me by the herein-before in part recited Letters Patent is-
Firstly. The use in the mariners' compasses known as liquid compasses of a box
or kettle with a transparent bottom.
Secondly. The use in liquid compasses of a lining forming a vacuum or air
chamber, substantially as and for the purpose specified.
In witness whereof, I, the said Nugent Wells, have hereunto set my hand and
seal, this Thirteenth day of September, in the year of our Lord One thousand
eight hundred and seventy-six.