Improvements relating to Telemetric Telescopes or Telemeters.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to Telemetric Telescopes or Telemeters.
I, WILLIAM SALT, of 65, Hatton Garden, London, E.C., Optician (being a
communication from Louis Lacombe, Fils, 9, Boulevard des Filles de Calvaire,
Paris, in the French Republic), do hereby declare the nature of this invention
to be as follows:-
My invention relates to single and double telescopes and binocular and mono-
cular field glasses and has for its object to provide a telescope with simple means for
measuring the distance of any object in the range of vision.
My invention consists in providing between the eyepiece and objective of a
telescope a micrometer or vertical scale of distance determined in units of
distance so that the distance of any object from the point of observation may be
determined by the adjustment of its image in a space between the lines of the
micrometer or scale that corresponds to the height of the image and in the
provision of an eye-piece as a divided lens, one part being the usual double con-
cave or other eye-piece lens, while the other is a double convex or other form of
magnifying lens so that when the telescope to which this eye-piece is applied iş
required to be used for ordinary observation the magnifying part of the eye-
piece may be covered, while when it is required for determining the distance
of any object from the point of observation the uncovering of the magnifying
part permits of the micrometer being discerned by thus being magnified.
My invention is applicable to telescopes generally and is more especially applic-
able to binocular glasses for military and field purposes.
In carrying my invention into effect in the provision of a telemetric telescope
in accordance with my invention, I provide an eye-piece which contains the eye-
lens and which is screwed or otherwise fitted to the extremity of the draw-tube
of the telescope, with a tube of smaller diameter, and of short length at the
opposite extremity of which a glass piece is provided which is marked by horizontal
lines constituting a micrometer or scale, the distance apart of such lines corre-
sponding to the height of the image of an object of known height at various
distances apart so that the image of the object may be adjusted into that space
that corresponds in height to that of the image, the distance of the object from
the point of observation may be thereby determined on reading off the distance
indicated on the gauge.
I so determine the scale of the micrometer that the spaces between the hori-
zontal lines shall represent the height of a man's stature at the distance indicated.
in that space: so that the telescope may be convenient for use in military opera-
tions. The spaces may of course represent the height of other objects at the
respective distances from the point of observation.
The eye-piece is formed as a divided lens one part, which is preferably the
greater part of the lens being an ordinary double concave or other eye-piece
lens, while the other is a double convex or other form of magnifying lens which

page_text: magnifies the micrometer or scale so that it may be clearly seen so that the
telescope may be used as a telemeter, while when the double convex or magnifying
part is covered, the telescope may be used for ordinary observation, the micrometer
or scale being not discerned.
I prefer to provide upon the frame of the eye-piece a shutter which hinges in
the plane of the lens and is capable of being closed to cover the double convex
or magnifying part and of being conveniently withdrawn to uncover that part
when the telescope is to be used as a telemeter.
In the provision of a binocular telescope in accordance with my invention I
provide one of the eye-pieces with a micrometer or scale as hereinbefore described,
do not limit my invention to any particular means of mounting the micrometer
or scale within the telescope as it is obvious that other suitable means may be
employed other than those herein before described.
Dated this 16th day of May 1898.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Improvements relating to Telemetric Telescopes or Telemeters.
I, WILLIAM SALT, of 65, Hatton Garden, London, E.C., Optician (being a
communication from Louis Lacombe, Fils, 9, Boulevard des Filles de Calvaire,
Paris, in the French Republic), do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to single or double telescopes or to binocular or mono-
cular field glasses and had for its object to provide a telescope with simple means
for measuring the distance of any object in the range of vision.
The invention consists in providing between the eye-piece and objective of a
telescope of whatever kind, a telemetric scale of distance in units of distance,
so that the distance of any object from the point of observation may be determined
by the adjustment of its image in a space between the lines of the telemetric
scale that corresponds to the height of the image; and in the provision of an eye-
piece as a divided lens, one part being the usual double concave or other eye-piece
or lens, while the other is a double convex or other form of magnifying lens,
so that when the telescope or like instrument to which this eye-piece is applied
is required to be used for ordinary observation the magnifying part of the eye-
piece may be covered, while when it is required for determining the distance of
any object from the point of observation the uncovering of the magnifying part
permits of the telemetric scale being discerned by thus being magnified.
The invention is applicable to telescopes generally and is more especially
applicable to binocular glasses for military and field purposes.
The invention is illustrated in the accompanying drawings in which:-
Figure 1 is a partial sectional plan of a binocular glass constructed in accordance
with the invention thereby furnishing a telemetric telescope specially suitable for
field and military purposes.
Figure 2 represents a front and side elevation of the transparent micrometer
gauge or scale.
Figure 3 illustrates the compound eyepiece employed in which an elevation is
given of the diametric abutting faces of the respective parts of the eyepiece.

page_text: Figure 4 is a front elevation of the eyepiece and frame having a shutter pro-
vided to cover the magnifying part of the compound lens.
In carrying the invention into effect in the provision of a telemetric binocular
giass in accordance with the invention and as illustrated in Figure 1 of the
drawings, I provide an eyepiece A which contains the eye-lens and which is
screwed or otherwise fitted to the extremity of one of the draw tubes B of the
glass, with a tube C of smaller diameter and preferably of short length at the
opposite extremity of which a glass or other transparent piece D is provided
which is marked by horizontal lines as shown in Figure 2, such glass piece
constituting a telemetric scale on which the distance apart of the lines correspond
to the height of the image of an object of known height at various distances
apart, so that in the use of the glass the image of the object may be adjusted
into that space that corresponds in height to that of the image, and the distance
of the object from the point of observation may be thereby determined on reading
off the distance indicated on the scale.
The scale is preferably so determined that the spaces between the horizontal
lines shall represent the height of a man's stature at the distance indicated in that
space so that the binocular glass may be convenient for use in military operations.
The spaces may however represent the height of other objects at respective dis-
tances from the point of observation.
The eyepiece is formed as a divided lens, one part A' preferably the greater part
of the lens, being an ordinary double concave or other eyepiece or lens, while the
other A² is a double convex or other form of magnifying lens which magnifies
the telemetric scale D so that it may be clearly seen when the glass is required
for use as a telemeter, while when the double convex or magnifying part A
is covered the instrument may be used for ordinary observation, the telemetric
scale being thereby not seen.
I prefer to provide upon the frame of the eyepiece A, a shutter E (Figures 1
and 4) which hinges in the plane of the lens and is capable of being closed to
cover the double convex or magnifying part A2, and of being conveniently with-
drawn to uncover that part when the instrument is to be used as a telemeter.
In Figure 4 the shutter E is shown uncovering the part A2 of the lens and is
shown in the same figure dotted in its closed position. It will be understood that
in the provision of a binocular telescope in accordance with the invention the tele-
metric gauge is only applied to one of the draw tubes.
Instead of providing a separate telemetric gauge the magnifying part of the
eyepiece may be replaced by a plain part upon which the gauge is indicated.
I do not limit my invention to any particular means of mounting the telemetric
scale within the telescope, as it is obvious that other suitable means may be
employed other than those herein before described.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A telemetric telescope or telemeter having an eyepiece provided of two parts,
the one being an ordinary double concave or other lens, while the other may be
provided for viewing a telemetric scale substantially as described
2 A telemetric telescope or telemeter having an eyepiece provided of two parts,
the one being capable of being covered by means of a shutter for the purpose of
uncovering or covering a telemetric scale substantially as described
3. A telemetric telescope or telemeter in which a telemetric scale is mounted
within the draw tube and in which the eyepiece is provided with a magnifying
part capable of being covered or uncovered by means of a shutter so that the
scale may or may not be discerned as it is required to use the instrument as a
telemeter or telescope.
4. A telemetric telescope or telemeter having an eyepiece of two parts, the one
being an ordinary double concave lens or other eyepiece, while the other is a

page_text: double convex or other magnifying lens, and a telemetric scale mounted within
the draw tube.
5. A telemetric telescope or telemeter substantially as hereinbefore described
and illustrated.
Dated this 16th day of Fahmi 1900
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and,
13, Temple Street, Birmingham, and 25, Cross Street, Manchester, Agents.