IMPROVEMENTS. IN THE MEANS AND APPARATUS FOR MEASURING ANGULAR AND ACTUAL DISTANCES
Year: 1860

page_text: Sealed the 7th August 1860, and dated the 10th February 1860.
PROVISIONAL SPECIFICATION left by the said Patrick Adie at the
Office of the Commissioners of Patents, with his Petition, on the 10th
February 1860.
I, PATRICK ADIE, of the Strand, in the County of Middlesex, Mathematical
Instrument Maker, do hereby declare the nature of the said Invention for
"IMPROVEMENTS. IN THE MEANS AND APPARATUS FOR MEASURING ANGULAR AND
ACTUAL DISTANCES," to 'be as follows:-
-
The object of the improvements is to arrange the 'apparatus so "that the
whole, angle observed may be shewn on the divided limb of circle or part of
circle on which, the angular readings are made, & further by means of a fixed
base in the modification hereafter described, to apply the angular parallax-to
the determination of the actual distance of any object from the observer.
The first aim is attained, by means of two sights or object glasses, or portions
of telescopes arranged one over the other, & having a totally reflecting prism or
prisms or other reflectors in: one or both axes diverting the rays so as to cause
them to unite, & be brought conjointly to one eye-piece or sight to which the
eye is applied in measuring. the angle. One. of these two object glassés or
sights, being directed to each of the different.objects whose angular distance is
required to be measured, & by. turning on the same centre thus give the 'true
angle undiminished. Also. to make any arc serve for an angle of greater extent
[Price 8d.]

page_text: I place a reflector occupying half the field in front of one of the telescopes, or
sights at a given angle.
The method of using the angular parallax as a measure of the distance of
an object, is by placing two object glasses or sights in the same plane at a
distance apart, reflectors being placed behind these objeci glasses or sights to
bring the cones of rays from these to one place, other reflectors being used to
take up portions of these cones, & unite them in one eye-piece or cye-sight;
one series of reflectors being attached to the fixed limb of the reading appa-
ratus & the other to the other end of the vernier arm. The angular
parallax or measure of the distance according to the angular position of
the reflectors being indicated by divisions shewing the relative position
of the limb & arm, thus giving a measure of the distance of the object
looked at.
I also propose a method of using the parallax as a measure of distance by
means of direct rays seen by a telescope or sight at one end & a mirror at the
other end of the base which is to be not, less than six inches long, which
mirror reflects into a second half mirror fixed so as to reflect the rays from
the first mirror into the telescope or sight, so that the eye receives both the
direct and reflected rays at once, the distance being determined by means of
the relative angle between the line of sight of the telescope & of the reflector
at the other end of the base; read on the divided limb as before.
on the
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Patrick Adie in the Great Seal Patent Office
10th August 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PATRICK
ADIE, of the Strand, in the County of Middlesex, Mathematical Instrument
Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of February, in the year of our
Lord One thousand eight hundred and sixty, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
the said Patrick Adie, Her special licence that 1, the said Patrick
Adie, my executors, administrators, and assigns, or such others as I, the
said Patrick Adie, my executors, administrators, and assigns, should at any
time agree with and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
me,
L

page_text: exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MEANS AND APPARATUS FOR MEASURING ANGULAR AND ACTUAL DISTANCES,"
upon the condition (amongst others) that I the said Patrick Adie, 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
Patrick Adie, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
The improvements relate to the application of two telescopes to reflecting
instruments, by means of new arrangements of the reflectors, whereby the
whole angle measured is represented on the limb of the instrument, these two
telescopes being used simultaneously with one eye-piece. For this purpose
I have a divided limb or circle, or portion of circle, with a vernier arm,
having one vernier or a plate with two verniers working on the centre of the
limb, the centre being hollow. One telescope tube carrying an object-glass is
fixed in or under the limb. In this tube, exactly under the hole in the centre,
is fixed a totally reflecting prism or other reflector, sending the rays at right
angles through the hollow centre. Another telescope is placed on the upper
side of the limb or circle to which the vernier arm or plate is attached.
Half of the field of this telescope is free for direct vision, the other half is
occupied by a prism or reflector at 45° to the centre, round which this telescope
(with the vernier plate) turns. This prism being fixed to and turning with the
telescope takes up the rays passed up through the hollow centre from the
telescope below the limb, and passes them out into the eye-piece simul-
taneously with those received by direct vision through the open half of the
upper telescope; thus one telescope being directed to the one object, and the
other to the other object whose angular distance is required to be measured,
and these two images being brought together on one edge of the half reflector,
a correct angular measure may be taken of the distance of these two objects
apart in full degrees.
The improvements, secondly, relate to the arranging of two telescopes or
object ends of telescopes with reflectors, in such manner that these may be
accurately applied to the determination of distances, by measuring the

page_text: angle formed by the cones of rays of said telescopes, such being placed a
given distance apart. For this purpose a very small arc only being neces-
sary, the limb and vernier arm are tubes, one inside the other, connected by
a centre near one end, or other required position, having a scale and vernier
at the other end. The two object glasses are placed on the same side, one in
each of these tubes at the opposite extremities. Behind each object-glass,
in its respective tube, are placed totally reflecting prisms, sending the rays in
each case towards the middle and through the inner tube. At the middle of
said tubes are fixed two smaller prisms, one in front of the other, the one also
attached to the vernier tube, and the other to the limb or outside tube, each
occupying half the field of the eye-piece, which is inserted halfway between
and on the opposite side to the object glasses; thus these, with their bent
rays, represent two telescopes used simultaneously with one eye-piece, and the
angle they form with one another is represented in degrees on the divisions
by the vernier.
But that the nature of my Invention, and means I adopt in carrying out
the same into effect, may be better understood, I will proceed to describe the
Drawings annexed, in the various Figures of which the same letters are used
to indicate like parts wherein they occur.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a side view in section of the first part of my improvements,
and Fig. 2 the same in plan. a, a, the upper telescope, and b the under one;
d, d, is the limb which, though represented a circle, may be also made a
segment of a circle. To this the inner hollow centre c, c, is firmly attached,
as also the lower telescope b. c', c', is the outer centre, to which the vernier
arm or plate is attached, as well as the upper telescope a, a; p is a totally
reflecting prism or other reflector which receives the rays from the object
glass b directed to one object, and reflects them through the hollow centre c, c,
into the prism or mirror p¹, which again reflects them into the eye-piece a³,
which also receives the direct rays from the object glass a', directed to any
other object, whose angular distance from that to which b' is directed is
required. The reflectors or prisms p and p' are attached and adjusted much
in the usual way at an angle of 45° to the plane of the instrument. d, d, is
divided on its inner edge at e, e, and d¹, d¹, has two or more verniers to read
off the angles by; d represents the tangent screw and clamp; at h, h, are
fixed semicircular sun shades, which are brought into use by means of small
handles outside the tubes.
Fig. 3 represents a plan in section, and Fig. 4 a side view, of the second

page_text: near one end or other
part of my improvements. d, d. d, d, represents the outer tube or limb of this
instrument, to which a short divided segment e is fixed; to d, d, d, d, is also
fixed an object glass at b', also a totally reflecting prism or other reflector at
pa attached in the usual manner. This reflector receives the rays formed by
the object glass b', and sends them up the inner tube d¹, d', d¹, d¹, to a
reflector or prism at p³, which sends them into the upper half of the eye-
piece a. The inner tube or vernier arm d', d¹, d', d', which carries a vernier
at g, has a female centre c¹, c', c, c. fixed to it
required position; this works on a male centre at c, which is fixed to the
limb or outer tube d, d, d, d, near one end or other required position. This
tube d¹, d¹, d', d³, has an object glass a' fixed to it at a given distance from b',
also a totally reflecting prism or other reflector p which receives the rays
from the object glass a¹, sends them up the inner tube d', d', d¹, d', to a second
prism or reflector p¹, fixed to this tube; also which prism p¹ sends them
into the lower half of the eye-piece a², thus when these two object glasses are
directed to the same object, the distance between a¹ and b' being known, the
angle between their directions may be read off on the limb e by the vernier
g, in whole degrees and the distance of said object ascertained. The adjust-
ment for the position of the tube d¹, d¹, d', d', to direct a', to the object is
made by the tangent screw d².
Having thus described the nature of my said Invention, and in what manner
I carry the same into effect, I would have it understood that I do not confine
myself to the precise details shewn and described, as these may be varied;
but what I do claim is, the means of reading angles by reflection in full
degrees, as applied and described in Figs. 1 and 2, and in Figs. 3 and 4; and
I also claim the means of using two object glasses directed to the same or
different objects, and so obtaining a simultaneous observation with one eye-
piece, in manner substantially as explained.
In witness whereof, I, the said Patrick Adie, have hereunto set my hand
and seal, this Tenth day of August, in the year of our Lord One
thousand eight hundred and sixty.
Witness,
THO. HENDERSON,
25, Sussex Place.
PATRICK ADIE. (L.S.)
i