IMPROVEMENTS IN APPARATUS FOR MEASURING DISTANCES, PARTICULARLY APPLICABLE TO WARLIKE PURPOSES.
Year: 1869

page_text: LETTERS PATENT to John Philip Nolan, of the Royal Artillery
Barracks, Shoeburyness, in the County of Essex, for the Invention
of "IMPROVEMENTS IN APPARATUS FOR MEASURING DISTANCES, PARTICULARLY
APPLICABLE TO WARLIKE PURPOSES.".
Sealed the 9th October 1869, and dated the 20th May 1869.
PROVISIONAL SPECIFICATION left by the said John Philip Nolan at
the Office of the Commissioners of Patents, with his Petition, on
the 20th May 1869.
I, JOHN PHILIP NOLAN, of the Royal Artillery Barracks, Shoe-
buryness, in the County of Essex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN APPARATUS FOR MEASURING DIS-.
TANCES, PARTICULARLY APPLICABLE TO WARLIKE PURPOSES," to be as follows:-
The object of this Invention is to construct a novel and peculiar
apparatus or instrument to be attached or secured to guns cither in
the field or in batteries, ships, or other structures, for more readily
measuring and estimating or calculating distances, particularly applicable
for warlike purposes.

page_text: The instrument comprised in these improvements consists of a pair
of angle measurers cach made up of two telescopes placed athwart cach
other. On the case of one of these telescopes an angular scalo decimally
divided is provided, and this case is in two places turned truly round
so that the whole instrument can revolve round the axis of this telescope
when it is placed resting in "V"" or supports provided for it (there
being cross wires in both telescopes).
To the second telescope is attached a limb furnished with a "vernier "
scale to read with more exactness the distance indicated on the scale
of its fellow. A roller or ruler constructed with movable rings, ends,
or slides is provided to mechanically calculate a distanco by means
of the angles furnished by the measurers, or by means of these angles,
togother with the base or linear space which may intervene between such
pair of angle measurers.
My improved apparatus with suitable modifications in its details is
intended to be applied to field, garrison, naval, or other warlike purposes.
For field purposes I attach two "V"" or supports to each of a pair
of field guns, on the right of one and on the left of the other. One
of the "V" is made so that it fits into the socket of a tangent sight,
and the other is affixed about fourteen inches in front, but both these
"V' "
bo otherwise affixed or made capable of being affixed at
other suitable parts on an emergonoy.
may
When there is no traversing arrangement with the gun I make the
rear "V" capable of shiding from right to left in a dovetailed stido
provided for the purpose.
I next provide a pair of instruments each consisting of a stout metal
tube turned truly round in two places to take the "V"" and having a
lump or swell at one end on which is divided a scale of quarter degrees
°
not marked in the ordinary manner but thus about
cloven times repeated; there may be numbers between the 0" to show
that the scale reads 10, 20, and so on up to 90. From one 0 to another
0 is 2 degrees, but this distance is not a necessary one. At the other
ond of this tube is a socket or rise to receive another corresponding
swell or hole on the limb. This tubo contains a "Hughegan" telescopo
with cross wires but no arrangement, allowing of focussing (except when
constructing the telescope). On the socket of the main tube I placo
a second telescope with a limb of about twelve inches in length firmly

page_text: attached; the limb has a “vernier” scale marked
".
2.
3.
///
and reads on the scale to 45 seconds. The limb is moved by a tangent
screw. A metal case covers the short or second telescope but is attached
to the first; its face or end nearest the object glass of the second telescope
is thickened and can be covered with a disc of paper.
It may here be mentioned that it is important that a plane passing
through the vertical-diameter of this paper disc should also pass through
a line perpendicular (or nearly so) to the axis of both telescopes.
A-second metal case covers and protects part of the limb, this case.
is also attached to the main telescope.
The form of mechanical calculator that I prefer to use is a cylinder
made by preference of wood about four inches in diameter and three
inches high.. It is composed of a block and of two rings made capable
of turning round the block. This roller or mechanical calculator is
arranged and so graduated as, firstly, to add two numbers (cach under
one hundred) together omitting hundreds in the answer; secondly to
find the side of an isosceles triangle with a small vertical angle when
the base and vertical angle or the sum of the base angles are known;
thirdly, to find the difference between two numbers each less than onc
hundred; fourthly, to find a distance when the vertical angle (or sum
of the base angles) and also the angle which a gun or other object of
known length at the other end of the base substends are known.
In using these instruments or apparatus for permanent batteries
or on board ship I make the following alterations. The "V" or
supports are fixed permanently in the battery or ship. The scale is
figured so as to read from 0 to 999 instead of from 0 to 99. The limb
or pointer of the second telescope is moved by a rack and pinion or by a
worm, but the peculiarity of the arrangement lies in the fact of the handle
being an electro-magnet, a corresponding piece of soft iron forming part
of the mechanism which moves the second telescope, so that by causing.
the electro-magnets which have been kept magnetised by a "voltaic"
current to become demagnetised at the same instant both telescopes.
are stopped at the same moment. The calculating roller is suitably
arranged and graduated to correspond to the necessary scale required
for a battery, ship, or other structure, the chief difference being that
an additional scale proportioned to the logarithms of the sines of angles
is added.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Philip Nolan in the Great Scal Patent Office
on the 20th November 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
PHILIP NOLAN, of the Royal Artillery Barracks, Shoeburyness, in the
County of Essex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of May, in the year of our
Lord One thousand eight hundred and sixty-nine, in the thirty-second
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Philip Nolan, Her special licence that
I, the said John Philip Nolan, my executors, administrators, and assigns,
or such others as I, the said John Philip Nolan, my executors, adminis-
trators, 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, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN APPARATUS
FOR MEASURING DISTANCES, PARTICULARLY APPLICABLE TO WARLIKE PURPOSES,'
upon the condition (amongst others) that I, the said John Philip Nolan,.
my executors or adıministrators, 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 tho
Great Scal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
13.
NOW KNOW YE, that I, tho said John Philip Nolan, do hereby declare
the nature of my said Invention, and in what manner tho same is to be
performed, to be particularly described and ascertained in and by the
following statement in writing, and on reference being had to the
accompanying Sheet of Drawings, that is to say :-
The object of these improvements is to furnish a speedy method of
measuring distances.
The instruments are of two kinds, one adapted chiefly for obtaining.
distances with an army in the field, the other for obtaining distances
from batteries or ships.

page_text: I will proceed, rst, to describe the former class. The instruments
and fittings consist of two metal Y" or " to each gun fitted with the
instruments consisting of a pair of angle finders of a roller or mechanical
calculator, and of a measuring tape wound round a spinning rack. The
best way of fitting the Y" or V's is to make the stem of one of them the
same shape as the tangent sight bar of a gun, so that it can he slipped
into the place of an ordinary tangent sight at will, and be fastened
permanently by screws or otherwise; à second Y or V is attached (per-
manently if required) about fourteen inches in front of the other to the
gun. The Y" or V" should be filed down and adjusted until the wires
of the angle finder when placed in them point to the same object as
do the ordinary sights of a gun at point blank, or at one thousand yards,
or other simple distance. Or instead of Y's or V" the front Y or V may
be replaced by a cup, and the rear Y or V instead of a straight shank
may have a shank cut in a segment of a circle of which the imaginary
centre of the cup will be the centre. In this case, a new segmental
groove must be made in the gun to take the shank of the hinder Y or V.
The object of this arrangement would be to allow the angle finder being
used as a telescopic sight.
Another modification to be used for guns which have no traversing
arrangement would be to make the head of the Y or V capable of
sliding in an undercut upon the shank receiving motion from a screw
to allow of the rear Y or V moving right or left, and thus pointing the
finder. The Y or V" may also be attached to stands from which the
angle finders can be used. The body or case of the angle measurer is
made of metal (brass, by preference), and may be either in one piece or
may be made of an interior tube and exterior case. It is turned truly
round in two places about fourteen inches apart (so as to fit and turn in
the Y", V", or supports), and provided with two shoulders, one at either
end. About one inch in front of the shoulder of the rear turned part
the shoulder or button of a socket should be firmly attached with screws
to a recess prepared for it in the case. In the interior of the case are
placed the glasses of an ordinary telescope furnished with erecting eye
piece object glass to screw into the fore part of the case, and an erecting
compound eye piece to fit tightly into the rear end, but any combination
of glasses which permit of cross wires being placed in the focus will
do. The object glass, eye piece, and wire piece are thoroughly focussed
to about two thousand yards distance and to ordinary sight the wires
are callimated, all these pieces are held firmly in their places in the

page_text: case by screws, the binding screws being in turn secured by smaller or
keeper screws driven through the heads into the case. Just behind
the shoulder of the fore turned part is a lump or swell of metal made
very strong. The upper surface of the lump is placed so as to present a
smooth surface parallel to the axis of the telescope and to the plane of
the socket. It may be electro-plated with silver, a scale is then divided
on it with the centre of the socket for centre, and twelve inches for
radius. The scale is composed of about eleven main spaces each, figured
or marked thus
the angular measurement from 0 to 0
is 2 degrees. The centre 0 may be placed over the longitudinal vertical
axis of the telescope, this is not however important.
The second chief part of the angle finder consists of a stout steel limb
provided with a swell or "vernier" scale at the fore end; at the rear
end is a hole cut conically to fit nicely the socket or button on the case.
Across the socket is a short telescope raised about half an inch from
the same. This telescope has an erecting oye piece, cross wires, and
an object. glass, and it is attached very firmly to the "vernier "
limb by screws or otherwise. A small circular flat plate with pins to
fit into corresponding holes in the socket, and a flat-headed screw to
screw into the socket are placed above the hole in the limb and serve
to attach it to the case of the main telescope. The vernier" at the
end of the limb is marked 1. 2.-10., but reads to halves, nineteen of
the divisions on the main scale correspond to twenty divisions on the
"vernier," thus reading to 45 seconds. The limb receives motion by a
tangent screw or other suitable arrangement. The tangent screw is
affixed to the case at a suitable point and passes through a button
tapped with a female thread attached to the limb and capable of
rotating. A cylindrical case of about 2 inchos interior diameter of
thin metal is placed over the short telescope to protect it from injury.
The end nearest the object glass of this case must be broadened, so as to
allow of a circular piece of white pasteboard or paper (of which the
centre is cut out) being screwed on it. This case is capable of easy
detachment from the main case or telescope.
In constructing the instruments it is important that the following
points should be attended to:-
That the axis or the centre wires of the short telescope should be
parallel to the unver face of the luun.

page_text: That the short telescope should be locussed for about seventy yarus
distance.
That the vertical diameter of the face of the case of thin metal should
be in such a position that a plane passing through it at right angles
to the axis of the main telescope should also pass through the centre
of the socket.
That, in a pair of instruments, in the right instrument the object glass
of the short telescope should be to the left of an observer looking
through the main telescope, and that the smaller numbers on the scale
and "vernier" should run from right to left.
That the tangent screw should have its handle to the right of the
main telescope:
That the broadened part of the thin case should be to the left or over
the object glass of the short telescope.
In a left instrument these directions would be reversed. There are
catches on the tangent screw which prevent the short telescope being
moved so far as to touch on cither side its protecting cover. A second
case of thin metal may or may not be attached to the main telescope
so as to cover and protect the steel limb from injury while allowing it
free motion until brought up by the catches on the tangent screw,
In using the instrument for permanent batteries, or on board ship the
following alterations are made:-
The limb is worked by a rack and pinion or by a worm, but the
peculiarity of the arrangement lics in the fact of the worm handle being
an electro-magnet, a corresponding piece of soft iron forming part of
the mechanism which moves the short telescope, so that by causing the
electro-magnets (which have been kept magnetised by a "voltaic" or
other current) to become demagnetised at the same instant both
telescopes are stopped at the same moment.
The calculating roller is likewise suitably arranged and graduated to
correspond to the necessary scale required for a battery, ship, or other
structure, the chief difference being that an additional scale proportioned
to the logarithms of the sines of angles is added.
Such being the nature and object of my said Invention for "Improve-
ments in Apparatus for Measuring Distances, particularly applicable to
Warlike Purposes," I will now proceed to describe more in detail the
manner in which the same is to be or may be performed or carried into

page_text: practical effect, and in order that the same may be distinctly understood
I have annexed hereunto a Sheet of Drawings illustrative thereof, and
have marked the same with figures and letters of reference corresponding
with those in following explanation thereof, that is to say :-
On the accompanying Sheet of Drawings Figure 1 represents a plan
view of one of a pair of instruments to be used with the left-hand gun,
the case enclosing one of the telescopes being shewn in red lines;
Figuro 2, a side elevation of the same.
Figure 3, a plan view of part of the "vernier " limb which is attached
to the second or top telescope.
Figure 4, a plan view of the socket on which the limb turns.
Figure 5, a front elevation of one of the "Y"," "," or supports for
sustaining the instrument.
Figure 6, a central section of the mechanical calculator, showing the
carpentry thereof and the way in which the movable rings are secured;
Figure 7, a top view of the same; Figure 8, a bottom view of the same;
and Figure 9, a side elevation of the mechanical calculator, the samic
being shown in this Figure on the accompanying Sheet of Drawings as
if it were unrolled in order that the system of marking or numbering
may be more clearly and efficiently defined.
The improved apparatus with suitable modifications in its details is
intended to be applied to either field, naval, garrison, or other warlike
purposes, as occasion may require.
For field purposes two Y" or V are attached at suitable distances
to each of a pair of field guns on the right of one and on the left of the
other.
When there is no traversing arrangement with the gun I make the
rear Yor V capable of sliding from right to left in a dovetailed slide.
The pair of instruments next provided cach consists of a stout melal
tube c truly turned at a', b', to rest in the Y" or V" x (Figure 5), so that
the instrument when resting in the Y", V", or supports provided for it
can revolve round the axis of the telescope b. There are cross wires in
both telescopes, the same being secured and set in metal tubes e and
adjusted in their proper places in cither telescope by screws, these are
secured by keeper screws *. The tube or casc c encloses a "Hughegan"
or other telescope b, admitting of the introduction of cross wires, and
has at one end a lump or swell y, on which is divided a scale d of quarter

page_text: degrees marked, as shown at Figure 1, from one 0 to another 0 is
degrees angular measurement, but this distance is not a necessary one.
At the other end of the tube c is secured a socket or rise &, Figure 4, to
fit in a corresponding hole in the limb g, Figure 3. On the socket
of the tube c is placed a second telescope a firmly attached by screws q
to the "vernier" limb g. The "vernier" his marked as shown and
reads on the scale d to forty-five seconds. The limb g is moved by a
tangent screw i with catches 1. A metal case & encloses the telescope a
and is attached to the telescope b, its face or end f¹ is broadened and
can be covered with a disc of
paper.
It may here be mentioned that it is important that a plane passing
through the vertical diameter of this paper disc should also pass through
a line perpendicular or nearly so to the axes of both telescopes.
A second metal oase can be made so as to cover and protect part of
the limb, this case being attached to the main telescope.
The form of mechanical calculator that I prefer to use is a cylinder
made by preference of wood three to four inches in diameter, and two
to three inches high. It is composed of a block and two rings l, m,
made capable of turning round the block. It is arranged and so
graduated as, firstly, to add two numbers (cach under one hundred)
together, omitting hundreds in the answer; secondly, to find the side
of an isosceles triangle with a small vertical angle when the base and
vertical angle or the sum of the base angles are known; thirdly, to
find the difference between two numbers, each less than one hundred;
fourthly, to find a distance when the vertical angle (or sum of the base
angles), and also the angle which a gun or other object of known length
at one end of the base subtends at the other are known. The circum-
ferences C and D of the roller are cach divided into one hundred equal
parts. A logarithmic scale is run round the circumference F. Another
logarithmic scale is run round E in the reverse direction. Above F may
be put a table of fuzes, so that the lengths of time of fuzes will be above
the ranges to which they are severally suitable. The bottom flat end
has similarly the rings A and B divided into one hundred equal parts.
The figures on B running in the same direction as C and D, and those
on A in an inverse direction. The scale H is logarithmic and runs in
an inverse direction to that.on F.
In making these scales care should be taken that the cypher of
scale A is exactly below that of D, that of B below that of C. Also

page_text: that the 60 or 40 on line D should DC tolerably well below the corres
ponding number on E. A mark in the shape of a gun may be made at
the cypher on C; an arrow with the word tape below it should be cut
at about the division 97 on F. Another index mark is cut on the face
opposite H, so that when the arrow with the word tape points to 50
on this index mark will point 90 or 89 on H. This is for a 12 lbs.
Armstrong gun, for other guns the mark will have to be placed so that
when the tape arrow points to the distance at which the guns, or rather
the two angle finders are apart the mark will point on II to 3rds of
the number of minutes subtended at that distanco by the interval
between the centre of the white face of the angle finder when placed on
the gun and the muzzle of the same gun. A stout measuring tape about
seventy yards long marked on both sides in yards and quarters of yards is
provided, and at every five or ten yards fishing swivels may be interposed.
The tape is wound round a plain rack composed of two longitudinal
pieces of wood with two or three cross bars, in the centre of the longi-
tudinal slips are two buttons or projections. The handle must be easily
detachable from the rack; it is a plain piece of thick iron wire with
hooks on the ends to take the buttons on the rack.
In constructing instruments for use on board ship, the following
differences are made:-
The lump y is made much larger so as to admit of a scale of about 125
degrees in breadth being placed upon it.
The short telescope a will be made larger, say, of about twelve inclics
in length.
The limb g will receive motion from a worm and cog wheel instead of
from a tangent screw.
The handle
of the worm will be made of soft iron.
With cach pair of instruments will be supplied a pair of small electro-
magnets connected by a wire. These magnets can be made to act as
handles to turn the worm that gives motion to the limb; as long as a
current of electricity (from a "voltaic or other battery) flows through
the wire round the two clectric magnets they will grip the soft iron
of the worm, but upon the current being interrupted they will detach
themselves simultaneously from the worm.
The singular scale d, of whatever extent, will be divided into portions
of 25 degrees; each of these will be divided into ten subdivisions, and

page_text: these again into ten others, thus the smallest divisions will each be one-
fourth of a degree.
The scale d will be marked as follows:-5,000 being pointed out by
the limb g when the cross telescopes a, b, are at right angles to each
other, or nearly so,
4000
5000
5100
5200
0123456780012345678901234567890
From 4900 to 5000 is 2 degrees angular measurement. A notched
bar will run underneath the instrument and a small weight being moved
along this bar will determine the levelling of the instruments. In this
case the Y" or V" to receive the instruments would be made fixtures in
the ship or battery.
The alterations in the roller would be as follows:-The lines A and B
need not be marked at all; C, D, E, F, would remain as before, but for
I would be substituted a scale of logarithmic sines, the sines increasing
from left to right. On the roller opposite to this scale would be made
an index mark.
The position of the index mark would be thus determined :-Set the
tape mark to the distance between the two pairs of Y" or V" in a given
ship or battery, or rather from the intersection of one pair of telescopes
to the intersection of the other; then make the index mark opposite the
figure representing on H the log. of sin. 90°.
Having now described the nature and object of my said Invention
for "Improvements in Apparatus for Measuring Distances, particularly
applicable to Warlike Purposes," together with the manner in which
the same is to be or may be performed or carried into practical effect, I
would remark in conclusion that I claim as my Invention, the improved
apparatus as herein-before fully described and illustrated on the accom-
panying Sheet of Drawings, or any mere modification or imitation
thereof, acting in the same or a similar manner, and I would hcrc
remark that I do not confine myself to the exact proportions or
dimensions of the different parts of the apparatus (as shown on the
Drawings or described) as the same may obviously be altered without
in any way departing from the characteristic or principal features of
my Invention; but I wish it to be distinctly understood that the points
or novelties I more particularly claim are,―
Firstly. The use of a pair of twin instruments working with cross
telescopes and measuring angles for rapidly taking distances

page_text: Secondly. The using an angle measurer so devised that the plane on
which the angle is recorded and also one of the legs of the angle
observed shall both revolve round the line of sight of the other leg of
the angle, so that theoretically when one leg of the angle has been fixed
the means of determining the other leg may be moved about to find the
second point of observation without interfering with the first half of the
observation, and that practically this may be nearly true.
Secondly. The using an angle measurer so devised that the plane on
which the angle is recorded and also one of the legs of the angle
observed shall both revolve round the line of sight of the other leg of
the angle, so that theoretically when one leg of the angle has been fixed
the means of determining the other leg may be moved about to find the
second point of observation without interfering with the first half of the
observation, and that practically this may be nearly true.
Thirdly. The affixing of Y" or V" to a gun to receive such an instru-
ment.
Fourthly. The employment of a special mechanical calculator to 1
determine distances, and more especially the exact form of a calculator
described above, and also its connection with the peculiar system of
notation employed upon the scale of the angle measurer.
The peculiarities in this scale arc,-
Firstly. The use of a decimal angular measurement instead of an 1
angular measurement in which degrees and minutes are used.
And, secondly. That in the field instruments it is of no consequence
between which pair of cyphers the angle is registered.
And, fifthly, and lastly. I claim the employment in ships of fixed
instruments of electro-magnetic angles to give motion to the recording 2
limb, so that by the interruption of a current of electricity both limbs
may be simultaneously stopped by the detachment of the handles.
In witness whereof, I, the said John Philip Nolan, have hereunto
set my hand and scal, this Twelfth day of November, in the
year of our Lord Oue thousand eight hundred and sixty-nine.
2
JOHN PHILIP NOLAN. (L.S.)
Witness,
BRISTOW HUNT,
Solicitor and Patent Agent,
1, Serle Street, Lincoln's Inn.