A NEW CONSTRUCTION OF A TELESCOPE OR OPTICAL INSTRUMENT FOR VIEWING DISTANT OBJECTS, & FOR OTHER USEFUL PURPOSES, WITH A SUITABLE TABLE OR STAND FOR THE SAME
Year: 1811

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CORNELIUS
VARLEY, of Junction Place, Paddington, in the County of Middlesex, Artist,
send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Seal of Great Britain, bearing date at Westminster,
the Fifth day of April, in the fifty-first year of His reign, did, for Himself,
His heirs, and successors, give and grant unto me, the said Cornelius Varley,.
His especial license that I, the said Cornelius Varley, my executors, adminis-
trators, and assigns, or such others as I, the said Cornelius Varley, my execu-
tors, administrators, or assigns, should at any time agree with, and no others,
from time to time and at all times during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "A NEW CONSTRUCTION
OF A TELESCOPE OR OPTICAL INSTRUMENT FOR VIEWING DISTANT OBJECTS, & FOR OTHER
USEFUL PURPOSES, WITH A SUITABLE TABLE OR STAND FOR THE SAME;" in which
said Letters Patent there is contained a proviso, obliging me, the said Cor-
nelius Varley, by an instrument in writing under my hand and seal, particu-
larly 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 Majesty's High Court of Chancery within two calendar months next and.
immediately after the date of the said recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Cornelius Varley, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, is described and ascer-
tained in the plans hereunto annexed, and the following explanation thereof
(that is to say) :-
My said Invention consists in combining one or two reflecting surfaces with
a simple kind of telescope that inverts the object, and thereby gaining an erect
image without any additional length to the telescope, placing the telescope out
of the way of the image, and apparently projecting the said image flat on a
table, so that it may be easily traced on paper, &c., the image being seen by
one eye, and the pencil or tracer by the other, or by both eyes, and of a table or
stand for supporting and using the same.
Figure 1 is an horizontal section of the telescope of the size I usually make
them when the magnifying power is to extend from four to nineteen times.
A, the object glass, which is achromatic; B, a plain polished speculum, placed
at an angle of 45° to the axis of the tube, (or it may be placed at B,
Figure 3, and attached by any of the convenient methods well known, in
which case the eye piece will always go in at the end, as shewn in the Figure);
Ga short neck or tube to receive the eye piece placed at right angles to the
tube, to receive the rays after reflection from the speculum B; D, the larger
eye piece, composed of two plane convex lenses a, a, six inches focus each,
their combined focus being three inches; placed with their convex sides to the
eye; their aperture, two inches or two-thirds the combined focus and of b;
the eye glass of two inches focus, placed two inches from the nearest lens a;
the flat side next the eye, the aperture half the focus. This eye piece
produces a perfectly correct image, and a very large field view of 60°, or it
may be made with two lenses, as Figure 2, in the same proportion of two
to three. c, a small plane reflecting metal speculum, placed before the eye
glass at an angle of 45°, as seen in Figure 3; the speculum produces an
erect image, and turns the cone of rays upwards, thereby making the objects
appear to lie upon the table, and in order that the artist may see the image and
the surface upon which it is to be drawn, at the same time this speculum is
réduced in the middle at the top to a sharp edge, as shewn at c, Figure 8, and
Figure 4, (which is a section at the upper edge of the metal,) the upper edge is
made to extend nearly through the cone of rays coming from the eye glass, by
which means the eye must be placed over the edge to see the image, and can
see the plane surface underneath it at the same time. e, e, Figure 5, the neck
of the eye piece (which is circular); d, d, a short piece of tube in which the
little speculum is fixed by screws, made to slide in the neck e, e, and kept in

page_text: its place by screws f, f, sliding in the holes g, g, (whereby the speculum may
be adjusted-to suit the cone of rays); the upper side of this tube, and of the
neck in which it slides, is filed away, so as to be in a line with the cone of the
eye piece, as seen, Figures 3.and 5, to make room for the eye to approach, so
as to look into the little speculum. Figure 6 is a front view of the eye piece,
to shew how the back of the little speculum and brass back, to which it is
screwed, are filed away. Figure 7 is the front of the little speculum, screwed
on the brass back; the dotted circle (Figure 1) on the little speculum is the
place where the pencil of rays should appear, a few of them being lost over its
edge. The speculum must be near enough to the eye glass to reflect the place
of the eye about the eighth of an inch above its upper edge, which is shewn by
the dotted lines (Figure 3) representing the cone of rays. Figure 3 is a vertical
section of the telescope, with the great metal B taken out, (leaving out the
dotted speculum B,) and the largest eye piece put in at the end, by which means
the image is shewn reversed, and may be etched at once on copper or drawn on
stone (in the German mode of printing) and printed the right way; also with
the shortest focus object glass A put in, which magnifies by four times, it being
eight inches focus h, h, h, &c. Figures 1. and 3 are the stops or diaphragms
to prevent false light from being reflected from the insides of the. tube ;, the
insides of the eye pieces also, as at i, i, are turned in rings. like the threads
of a screw, to prevent light being reflected therefrom; k, k, Figure. 2, is a cap
to keep the small-speculum clean when not in use; 1, 1, Figure 2, is a neck
fitting in the larger one C, to receive the smaller eye piece, and.to.keep the
edge of the speculum c at the same distance from, the tube as the speculum of
the largest eye piece. The smallest eye piece that I find convenient to use, is
composed of an inch eye glass, with the second lens an. inch and half focus;
therefore, when very high powers are.wanted, a much longer focus object glass
must be used, which may be attached to the larger tube E, E, in the usual way.
Figure 8 is a perspective view of the eye piece; the eye pieces are made to
slide into the neck rather than screw in, that the telescope may be turned either
to the right hand or to the left; the eye piece in these telescopes is at the
largest end, excepting when long focus object glasses are used, it being requisite
to have large eye pieces for the lowest powers, and large eye pieces are much
pleasanter to use than smaller ones. The more these instruments, magnify. the
more sensible is the least shake or motion of the instrument, and therefore it was
necessary to construct a stand or table to support.it in use as steadily as possible,
which I have effected in the following manner :-Figure 9 is a perspective view
of the stand, with the telescope in its place; A, a framed table two feet square;
B, the front leg or support of it, which is made of three rods or bars of wood

page_text: jointed firmly together at the bottom without the least shake, and at the upper
ends, immoveably attached to blocks under the table by pins in the three most
distant points b, b, b, Figure 10 (which is the under side of the table; c, the
front of the table ;) D, D, the two other legs, each made of two pieces jointed
firmly together at bottom (Figure 11 is one of the legs open as when put in
the table), and also attached to the table by moveable joints as near as possible
to the fastenings of the first leg, that the different legs may form triangles with
each other, the earth or floor forming their base. d, d, Figure 10, are two
places for one leg; and e, e, the two places for the other, which receive the
circular joints f, f, Figure 11, and of the other leg also, which are made
parallel to each other when open, in order that the legs may turn freely in or
out, by which means the table may stand even upon any sloping or uneven
ground; these legs are made to take on or off by seven steel pins at b, b, b,
d, d, and e, e, Figure 10. Figure 12 shews the seven bars forming the legs
fastened together by two rings g, g, to render them portable; Figure 13 is a
section of them, showing how the bars are formed to lie well together. Figure
14 is a section across the joints at D, B, Figure 12, a little separated to shew
which are joined together; i, i, i, are brass hinges; B are the joints of the front
leg, the middle rod, which is round, being jointed to the two others by three
iron staples m, m, m; Figure 15 is a side view of the joints which is placed
exactly opposite the joint of the brass hinge; Figure 16 is the joint of the
other legs; Figure 17 is a side elevation of the table; n, the round rod which
passes from the joint B into the block o, at the back of the table; Figure 18
is a back elevation, showing the spreading out of the two legs D, D, which are
drawn in or let out by strings p, p, which have loops to catch on the pins q, q, in
the two front blocks. To support the telescope, two thin triangular frames 1, r,
are hinged on to the sides of the table, and made fast together at top by hooks
8, 8; t, t, Figure 9, is the telescope with the eye piece in the side, for shewing
objects the right way to support the other end; a triangular frame w is made
to hinge on to the frame r, having at top a moveable piece of wood * (sliding
under a screw) with a notch to hold the telescope; y, y, a bar of wood hooking
on to the framer, having at the other end holes to receive a pin in the side of
the slide, by which the telescope may be supported in any part at pleasure.
These frames are all put on with hinges as Figure 20, to hook on or off, so
that when the telescope is wanted to point to the right hand, the frame w may
be taken off and put on the hinges z, z, on the right-hand frame r. Figure 19
is an end view of the telescope, shewing the manner of fitting it to the frames
, r; it is kept in its place by a cord or ribband wrapping round it and secured
by pins; Figure 17 shews the top of the frames inclined backwards to bring

page_text: the eye piece over the middle of the table; Figures 17 and 18 show the
telescope with the eye piece in the end, by which means the object is reversed,
in which case it is supported under the frames r, r, by a piece of wood 1, 1,
sliding through the frames, and at the back by another triangle 2, 2, hooking
to the back of the board with a similar slide to x, on the frame w, to hold the
telescope, so that the supports are every way made by triangles.
In witness whereof, I have hereunto set my hand and seal, this Fourth
day of June, in the year of our Lord One thousand eight hundred
and eleven.
AND BE IT REMEMBERED, that on the same Fourth day of June,
in the year above mentioned, the aforesaid Cornelius Varley came before
our Lord the King in His Chancery, and acknowledged the Specification
aforesaid, 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 same Fourth day of June, in the year above written.