AN INSTRUMENT OR GONIO- METER, WHICH WILL MEASURE OR LAY DOWN ANGLES TO MINUTES FROM THE SMALLEST RADIUS'S TO ANY EXTENT, DRAW CIRCLES TO ANY RADIUS, DRAW AND MEASURE ALL KINDS OF RIGHT-LINED FIGURES MADE USE OF IN GEOMETRY, TRIGONOMETRY, AND NAVIGATION, WITH AN ACCURACY AND DISPATCH HITHERTO NOT KNOWN, WHICH INSTRU- MENT I CALL THE HARTESIAN GONIOMETER; AND A CLAMP APPLICABLE THERETO, AND TO OTHER USEFUL PURPOSES; AND ALSO A NEW SUSPENSOR AND ORBICULAR CASTOB, APPLICABLE TO MARITIME AND OTHER PURPOSES
Year: 1801

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, NAPHTALY
HART, of Pimlico, in the County of Middlesex, Gentleman, send greeting.
WHEREAS His present most Excellent Majesty King George the Third,
in and by His Letters Patent under the Great Seal of the United Kingdom
of Great Britain and Ireland, bearing date at Westminster, the Third
day of December, in the forty-second year of His reign, did give and grant
unto me, the said Naphtaly Hart, my executors, administrators, and assigns,
His especial licence, full power, sole privilege and authority, that I, the said
Naphtaly Hart, my executors, administrators, and assigns, and every of them,
by myself and themselves, or by my and their deputy or deputies, servants or
agents, or such others as I, the said Naphtaly Hart, my executors, adminis-
trators, or 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 use, exercise, and vend, within that part of His
said Majesty's United Kingdom called England, His Dominion of Wales, and
Town of Berwick-upon-Tweed, my Invention of "AN INSTRUMENT OR GONIO-
METER, WHICH WILL MEASURE OR LAY DOWN ANGLES TO MINUTES FROM THE SMALLEST
RADIUS'S TO ANY EXTENT, DRAW CIRCLES TO ANY RADIUS, DRAW AND MEASURE ALL
KINDS OF RIGHT-LINED FIGURES MADE USE OF IN GEOMETRY, TRIGONOMETRY, AND
NAVIGATION, WITH AN ACCURACY AND DISPATCH HITHERTO NOT KNOWN, WHICH INSTRU-
MENT I CALL THE HARTESIAN GONIOMETER; AND A CLAMP APPLICABLE THERETO, AND
TO OTHER USEFUL PURPOSES; AND ALSO A NEW SUSPENSOR AND ORBICULAR CASTOB,
APPLICABLE TO MARITIME AND OTHER PURPOSES;" in which said Letters Patent
there is contained a proviso obliging me, the said Naphtaly Hart, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of my said Invention, and in what manner the same is to
be performed, and to cause the same to be inrolled in His said Majesty's
High Court of Chancery within one calendar month next and immediately
.

page_text: after the date of the said recited Letters Patent, as in and by the same,
relation being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Naphtaly Hart, do hereby describe and ascertain the nature of my said Inven-
tion, and the manner in which the same is to be performed, by the Plan or
Drawing in the margin of these Presents, and as follows, that is to say:
Figure 1, the Goniometer, made of metal, wood, ivory, or of any substance
capable of performing what is requisite, the exterior shape of which may be
square, circular, pentangular, or any other suitable form, and consists of the
following parts:-A, A, A, A, the fixed circle, so called because it remains in
one position during the performance of several problems. It is first graduated,
each quarter into ninety degrees, and those again subdivided into such minute
parts as the radius of the instrument will permit, in order that by the assist-
ance of the nonius herein-after mentioned the divisions may be read off to
minutes, or more minute parts. And altho' I have graduated the instrument
in the figure annexed to each ten degrees only of the quadrant, yet it will be
easily understood by those who make or graduate instruments, or others
possessing the smallest idea of dividing circles. 2dly, each quarter is further
divided into cight parts for the points of the compass, and again subdivided"
into quarter points; but I mean to graduate the said circles, or add to them
others graduated into decimal, whole, or broken numbers, in such manner as I
may find necessary for applying the instrument to various purposes. B, B, B, B,
the moveable circle, the whole of which, with it's appendages, are shaded in the
Drawing hereunto annexed, to render it more conspicuous. It is let into the
fixed circle, and kept therein by means of a cell, groove, screws, points, or any
other mechanical contrivance whatever, but so that it may turn round in the
fixed circle perfectly close, free, smooth, even, and regular. Fixed to the said
moveable circle is, first, a broad piece of, metal, wood, or any other suitable
substance, as in the old whole protractors, with it's edge to serve as the
diameter of the instrument, as shewn at M, M, graduated differently as various
purposes may require, but in general only to even parts. Below it is a groove,
slit, or dovetail, C, C (connected with another groove, slit, or dovetail, also -
marked C, vertical to it, for carrying a semi-eliptic compass, herein-after men-
tioned). In the grooves C, C, is a cursor or slide carrying D (with or without
a nonius, as may be required), on which D is a cylinder, as shewn by the
circle L, for the purpose of fixing a pen, pencil, or tracer in, to draw right
lines and circles, which cylinder may move in all directions by slides, or other-
wise graduated if required. Again, on the broad piece of metal, wood, or
other suitable substance as above mentioned, and perfectly coincident with and-
in an exact right line with the diameter M; M, is placed the nonius, and of
;

page_text: which several may be made if required for greater accuracy; the shape of
which may be varied so às best to suit the size of the instrument, or any
particular purpose which may be desired, and which said nonius is to be
graduated to minutes, decimals, or any other numbers which may be also
required. It is distinguished by a black line marked N, N, N, under which is
wrote Nonius. E is a sliding piece annexed to the moveable circle, and occa-
sionally fastened to the fixed circle by means of the screw F, in order to give
a more nice adjustment with the micrometer screw G; but I intend to apply
any other mode for giving motion to the moveable circle, and to all or any of
it's appendages, by means of any known mechanical power whatever which may
scem best adapted to any purpose required. II is a pin with a nutt or head for
turning the moveable circle round by hand. K, K, is a semi-eliptic compass,
superior to any yet offered to the public. It's merit consists in this, viz, that
the boxes on the cursors or sliders are not only flung out of their centers, but
also out of the center of the trammel, by which means the boxes may be made
nearly to meet together, notwithstanding the length of the trammel, and there-
fore describe clipses to very small diameters. They are shewn at Figure 21
upon a large scale, and in a more comprehensive way than on the gonio-
meter, and they will perform in a manner so as to permit the artist or
others to draw on a smaller, and also to an equal extent with
any hitherto
made (allowing equal sized instruments for any great extent). I, in dots, at
the side of the instrument, is a piece of metal, wood, or any other proper
material, of which several are intended to be variously attached to the instru-
ment, for the purpose of using clamps, weights, or any other thing, in order to
keep the goniometer steady, as also the paper or parchment, or whatever may
be drawn on.
The goniometer is also intended to be furnished (where persons will go to
the expence) with microscopes, lenses, or other apparatus for reading or laying
of with the greatest accuracy..
Figure 8, the Clamp. -It consists of two parts R, R, joined together by the
hinge Y, which permits it to be opened for the purpose of putting in a roll of
paper, parchment, or anything to be drawn on, as in large plans, which
done, it is shut. The pin W is put into the hole X, and it is then used as a
clamp. By this means the instruments, where it is necessary to use clamps,
will not only be kept steady, but also the paper, parchment, or other thing
to be drawn on, whatever their size, on which they are drawing.
Figure 4, the Orbicular Castor.-It consists of A, A, a piece of wood, metal,
or any other suitable substance, with an eliptical cell in it, the semi-conguagate
iameter of which is very little more than the radius of the ball B, made also

page_text: of wood, metal, or any other suitable substance, but it's transverse diameter is
somewhat enlarged to give the ball play. C, C, a piece of wood, metal, or any
other suitable substance, with a curved hole corresponding to the convexity of
the ball B, and which is fastened to A, A, and prevents the ball from falling out;
in the Drawing it is shewn with it's screws D, D, but any other mechanical
device may be used to answer the same purpose.
Figure 5 is the Suspensor, and which may casily be conceived by supposing
an oblong piece of anything capable of answering the purpose to be bent so
that its two internal sides may be paralel, leaving an aperture betwixt them
equal to the thickness of the bolt P, or the flat-headed pin, Figure 7, that it
may slide to a certain distance therein. It is cut open, as at C, to receive
a similar piece of wood, metal, or any other suitable substance, as shewn at
Figure 6, made equal in height to the aperture at C of Figure 5, through
which Figure 6 is put, and embraces the pin P by means of its aperture, and
being pushed home and then turned about, so as to permit the swinging with
case on the pin P, they are then both applied to the timbers, planks, or any
other suitable or proper place where their services may be required, and to
which each is respectively to be fastened with bolts, pins, screws, or in any
other manner as may be thought necessary. It will be found impossible
(using the seaman's expression) to unship them, and it is hoped they will he
of material service in, and applicable to, the hanging of ships' rudders, as many
accidents connected with them from that cause will be precluded. Nor is the
private property of individuals less concerned, for doors, hung in a similar
manner, cannot be uplifted unless they or their posts, or whatever else they
may be affixed to, break or give way.
In witness whereof, I, the said Naphtaly Hart, have hereunto set my
hand and seal, the Thirtieth day of December, in the forty-second
year of the reign of our Sovereign Lord George the Third, by the
grace of God of the United Kingdom of Great Britain and Ireland
King, Defender of the Faith, and in the year of our Lord One thousand
eight hundred and one.

page_text: AND BE IT REMEMBERED, that on the Thirty-first day of December,
in the year above mentioned, the aforesaid Naphtaly Hart came before our
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained, in form above written. And
also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.
Inrolled the First day of January, in the year above mentioned.
Inrolled the First day of January, in the year above mentioned.