AN ANTIMETER OR REFLECTING SECTOR, WITH ITS APPENDAGES FOR MEASURING ANGLES ACCURATELY BY LAND OR SEA
Year: 1781

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
GARRARD, of Gloster Buildings, Newington, in the County of Surry, Gentle-.
man, send greeting..
WHEREAS His most Excellent Majesty King George the Third, by His
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-first day of March, in the twenty-first year of His.
reign, did give and grant unto me, the said William Garrard, my executors,.
administrators, and assigns, and every of them, by myself and themselves, or
by my and their deputy and deputies, servants or agents, or such others as I;,
the said William Garrard, my executors, admors, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter.
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within that part of His Kingdom of Great Britain,
called England, His Dominion of Wales, and Town of Berwick-upon-Tweed,.
my Invention of "AN ANTIMETER OR REFLECTING SECTOR, WITH ITS APPENDAGES
FOR MEASURING ANGLES ACCURATELY BY LAND OR SEA," in such manner as to me,.
the said William Garrard, my executors, admors, or assigns, or any of them,
should in their discretions seem meet, and that I, the said William Garrard,
should and lawfully might have and enjoy the whole profit, benefit, commodity,
and advantage from time to time coming, growing, and arising by reason
of the said Invention, for and during the term of years therein mentioned;
to have, hold, exercise, and enjoy, the said licence, powers, priviledges,.

page_text: and advantages therein-before granted unto me, the said William Garrard,
my executors, administrators, and assigns, for and during and unto the
full end and term of fourteen years from the date of the said Letters
Patent next and immediately ensuing, and fully to be compleat and ended,
according to the Statute in such case made and provided; in which said
Letters Patent there is contained a proviso obliging me, the said William
Garrard, by an instrument in writing under my hand and seal, to cause a
particular description of the nature of my said Invention, and in what
manner the same is to be performed, to be inrolled in His Majesty's High
Court of Chancery within four calendar months next and immediately after
the date of the said Letters Patent, as in and by the same (relation being
thereunto had) may more fully and at large appear.
NOW KNOW YE, that in compliance. with the said proviso, I, the said
William Garrard, do hereby declare that my said Invention of an Antimeter or
Reflecting Sector, is described in the manner following, that is to say :-
The antimeter holds the nature of. Hadley's quadrant, but hath two index
glasses. The lower is placed in the center of the index, and the upper a small
distance farther on, a right line passing from the 0 division of the limb through
the center of the index affixed at any certain distance by a peculiar method of
adjustment being moveable by a screw and dovetailed groove. The sight
vane, or that which carrieth the telescope, is also adjusted by a screw and
groove, to suit the position of either of the index glasses. The instrument is
called a sector, because it will measure any angle, large or small, without
regard to the length of its arch. The lower index glass is not fixed down to
the index, but to a circular brass plate, and will move with the index or retain
its position while the index is moving, by being cramped with a screw to the
instrument itself. Under this glass, upon the index at the center, is fixed a
semicircular brass plate, in such position that the axis of the index is a tangent
to it.
With the upper index glass, upon the upper center, are two circular
brass plates; the under one hath a narrow continued part which reacheth
beyond the lower center, and is acted on by the semicircular plate when the
index is in motion, and counteracted by a spring with this continued part; the
upper plate, carrying the upper index glass, will move concentrically, or may
retain its position while the under plate is moving, by being cramped with a
screw to the instrument itself. The motion communicated from the index to the
upper index glass partakes of the power of the lever, and suffers a diminution
proportioned by the distance between the two centers and the radius of the
semicircular plate at the lower center. In this manner the same arch, which
is divided to minutes only, may be read off to any degree of accuracy; and all

page_text: year above mentioned, the said William Garrard came before our said Lord
the King in His Chancery, and acknowledged the Specification aforesaid, and
all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stampt according to the tenor of the
Statute made in the sixth year of the reign of the late King and Queen
William and Mary of England, and so forth.
Inrolled the same day and roar above mentioned