A NEW-CONSTRUCTED AZIMUTH AND AMPLITUTE COMPASS AND QUADRANT FOR THE IMPROVEMENT OF NAVIGATION AND PRACTICAL ASTRONOMY
Year: 1779

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GABRIEL
WRIGHT, of Fleet Street, in the City of London, Mathematical Instrument
Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of Great Britain, bearing date
the Twenty-fifth day of June, in the nineteenth year of His reign, give and
grant unto me, the said Gabriel Wright, His especial licence, that I, the
said Gabriel Wright, during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
Town of Berwick-upon-Tweed, my Invention of "A NEW-CONSTRUCTED
AZIMUTH AND AMPLITUTE COMPASS AND QUADRANT FOR THE IMPROVEMENT OF
NAVIGATION AND PRACTICAL ASTRONOMY;" in which said Letters Patent there
is contained a provisoe obliging me, the said Gabriel Wright, under my hand
and seal, to cause a particular description of the nature of my said Invention,
and how the same is to be perform'd, to be inrolled in His Majesty's
High Court of Chancery within four calender months after the date of the
said recited 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 provisoe, I, the said
Gabriel Wright, do hereby declare that my said Invention of A New-con-
structed Azimuth and Amplitude Compass and Quadrant for the Improve-

page_text: provements made by
me.
Ivory having
vist a horizontal Nonius (or Verniers) division on
a vertical motion by tooth and punion
| work within side and a brass mill'd nut to move the tooth and pinion on the outside of the Kittle or Compass Box. Figure
1 represents the new constructed Index and sights which
goes on the Compass Box its for observing the Sun thro' when the
Azimuth or Amplitude is takin of it's made of Brass or other mettal. There are twe réflecting Glass Mirrours placedt at
right angles to euch other on the plane of the Inder at A & B. also a screen or did Glass C. a convex Glass D all in mettal
frames to the vertical sight I is fixed a horizontal one E for the Eye to look down on the reflecting Glassts Jo to view the Sun of the
houzon of the Sea and to read of the Degrees from the Card Pr thro the convex Glass D... at the other end of the Index at F' is placed a brass
or lead weight this moves on a center at & to ballance or counterpoise the whole. Fige 2 is the improved reflecting Quadiant or Octant having
the following new parts. vij. a round picle of brass or other mettal with a miltit Edge II its so fasten it to the Indix of the Quadrant asto move
by hand or other ways round the anter of the Index carrying the Index Glass with it and is fasten'd to any position or angle required by a brass camp F-seru
I which is made fust to the upper part of the Index and has a Fine horizontal screw I to adjust the Induc Gluss to the horizon Glass at pleasure I
is a piece of Brass screw'd fast to the Quadrant frame having a fine devision cut on it and which is adjusted by two small screws to conside, with a like,
devision cut on the edge of the round plate H. A hole is likewise made thro' the round plate for a screw to go thro' it into the brass price I. to make it fast
to the divisions before mentioned at pleasure while the Index is moved back ninety Degrees there is likewise another screw M. this goes thro'a circular Slit or opening in the
round plate H. and screws it intirely fast to the Index of the Quadiant at pleasure. Cross the index Glass in a horizantul position is a fine line made of wire hair
silk or thread its fasten'd behind the Glass to the Brass Clip. the sight vane N is made with an • opening or slit having a piece of thin brass with a hole in
-the center to slide up and down it at pleasure so as to view objects in the tue plane of the Quadrant this sight is fastened to the fame by a horazantal mille krew and
removed at pleasure for a brass frame 0 corriping a fine Hair wire sick or thread line made to adjust in a vertical position by two small screws it.
where the Vane N. es taken from and fasten'd by the horizantal Screw R. Pis a moveable sight Vane with two lines drawn was the inside on mettal or Trou and is
fastened to the Arch of the Riadiant by a screw or other convenient method you look thio this sight when the quadrant is used with the Compass in taking the Suns &
Azimuth and Allitude at the same time I is a reflecting Glass in a brass frame apply'd occasionally to the Quadrant Frame to view objects when at the distance
from 140 to 180 degrees. Frigε 3 is a cylindric but with two parallel Glass Sides his filled, Oil Spirits water or any other fluid that may be thought proper for fleating
a perpendicular made of a fine hair Silk Where or thread line or other substance to be suspended by a Cork Ball or other light body that will float and an
or compound Ball that will gravitate.
Iso as to keep the line perpendicular in the fluid. A fine steel needle suspended at the end of a magnet has the same effect-
its use is to level the Compass by when the Hoiyan of the Sea cannot be observed. The parts above described may be made in brass or other mettal either simple or
compound Ivory or Ulood and the reflecting parts, which are of Gluss. may. : be either parallel sides or prisms or pellishd mettal Speculums or any other body that
reflects light will do the parts which are made to move by hand or adjust by Screws fo be done with tooth and pinnion work worn und endless
screw Leaver or Wheels or any other contrivance or method made use of by Mechanics all of which are.
with
may
- goes into the place
& Ivory mettal
· only different modles of doing the same thing...