A MODE OF PROTECTING THE MARINERS' COMPASS AGAINST LOCAL ATTRACTION
Year: 1859

page_text: LETTERS PATENT to Michael Henry, of 84, Fleet Street, in the City of
London, Patent Agent, for the Invention of "A MODE OF PROTECTING
THE MARINERS' COMPASS AGAINST LOCAL ATTRACTION."-A communication
from abroad by Samuel C. Bishop, residing at. New York, in the
United States.
Sealed the 18th October 1859, and dated the 11th May 1859.
PROVISIONAL SPECIFICATION left by the said Michael Henry at the
Office of the Commissioners of Patents, with his Petition, on the 11th
May 1859.
I, MICHAEL HENRY, of 84, Fleet Street, in the City of London, Patent
Agent, do hereby declare the nature of the said Invention for "A MODE OF
PROTECTING THE MARINERS' COMPASS AGAINST LOCAL ATTRACTION," communicated.
to me from abroad by Samuel C. Bishop, residing at New York, in the
United States, to be as follows:
My Invention consists in lining the compass box or binnacle with gutta
percha or other insulating substance so applied as to completely enclose the
compass, and so insulate it from the attraction of any surrounding bodies.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Michael Henry in the Great Seal Patent Office on the
8th November 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL
HENRY, of 84, Fleet Street, in the City of London, Patent Agent, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day. of May, in. the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Michael Henry, Her special licence that I, the said Michael
Henry, my executors, administrators, and assigns, or such others as I, the
said Michael Henry, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "A MODE
OF PROTECTING THE MARINERS' COMPASS AGAINST LOCAL ATTRACTION," commu-
nicated to me from abroad by Samuel C. Bishop, residing at New York, in
the United States, upon the condition (amongst others) that I, the said
Michael Henry, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Michael Henry, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement thereof, as communicated to me, reference being had to the
accompanying Drawings, and to the letters and figures marked thereon,
that is to say:-
This Invention consists in lining the compass box or binnacle with gutta
percha or other insulating substance so applied as to completely enclose the
compass, and so insulate it from the attraction of any surrounding bodies.
To enable others to apply this Invention to use, I proceed to describe it
with reference to the Drawings, in which Figure 1 is a central vertical
section of a mariners' compass and its box, with the aforesaid improvement

page_text: applied; Figure 2 is a perspective view of the compass and box, with the
cover of the box removed; and Figure 3 is a perspective view of the cover
of the box, showing it in an inverted position. Similar letters of reference
indicate corresponding parts in the several Figures.
A is the compass bowl, suspended in the usual gimbal ring B, whose
pivots b, b, are supported in bearings in plates a, a, secured to the sides of the
box; C is the box, and D is the cover. The box C is completely lined with
gutta percha c, c, which also covers the margin, as shewn at c¹, c. The
cover D has also a complete lining d, d, of the same material, except that
part of the head which receives the glass e, e, which unites with the gutta
percha to form a complete lining of insulating substances. The gutta percha
lining d, d, of the cover is also continued all around the margin, as shown
at d', d', and at each corner of the cover there is attached to the lining a
pin h of gutta percha to fit within the box C, to confine the cover in all
directions laterally. The box and cover are provided with hooks and
staples f, g, or other fastenings on opposite sides to confine the marginal
covering c, c, and d', d¹, of the box and lid closely together all around, so
as to complete the enclosure of the compass. The screws or other fastenings
used to attach the bearing plates a, a to the box should also be insulated
from the plates by means of washers or collars of gutta percha. Other
insulating substance may be substituted for the gutta percha, but the Inventor
prefers that substance, both on account of its excellent quality as an insulator,
and of the facility with which it can be applied.
What I claim as the aforesaid Invention (communicated to me), and desire
to secure by the herein-before in part recited Letters Patent, is, lining the
compass box or binnacle with gutta percha or other insulating substance, so
applied as to completely enclose the compass for the purpose of insulating it
from the attraction of surrounding bodies.
In witness whereof, I, the said Michael Henry, have hereunto set my
hand and seal, this Twenty-seventh day of October, in the year One
thousand eight hundred and fifty-nine.
Witness,
S. E. A. NEWSOME,
84, Fleet Street.
M. HENRY. (L.S.)