IMPROVEMENTS IN TELESCOPES WHEREBY THEY ARE RENDERED AVAILABLE FOR MEASURING DISTANCES
Year: 1876

page_text: LETTERS PATENT to William Lloyd Wise, of Chandos Chambers, Adelphi, in
tho County of Middlesex, for the Invention of "IMPROVEMENTS IN TELESCOPES
WHEREBY THEY ARE RENDERED AVAILABLE FOR MEASURING DISTANCES." A
communication from abroad by Wilhelm Klinkerfues, Professor and Director
of the Royal Observatory at Göttingen, Hanover.
PROVISIONAL SPECIFICATION left by the said William Lloyd Wise at the
Office of the Commissioners of Patents on the 28th June 1876.
WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the County of Mid-
dlesex. "IMPROVEMENTS IN TELESCOPES WHEREBY THEY ARE RENDERED AVAILABLE
FOR MEASURING DISTANCES." A communication from abroad by Wilhelm Klin-
kerfues, Professor and Director of the Royal Observatory at Göttingen, Hanover..
This Invention has for its object improvements in telescopes whereby they are
rendered available for measuring distances.
For this purpose, in combination with the lenses of the ordinary telescope, I use
a transparent diaphragm, having marked thereon a scale, arranged as herein-after
described.
In telescopes according to this Invention for nautical purposes I also employ
mirrors, as herein-after mentioned, for obtaining an artificial horizon.
To enable the nature of the Invention to be more readily understood I append a
Sheet of Drawings shewing one arrangement of tolescope, but I desire it to be
understood that the Invention is not limited to the precise arrangement illustrated.
Fig. 1 is a central vertical section; Fig. 2 is a plan; Fig. 3 is an end view of the
transparent diaphragm.
Fig. 4 is an end view of the telescope looking towards the object glass.
Fig. 5 is an enlarged view illustrating the general arrangement of the scale as
used for land purposes.
It is to be understood that the mirrors shewn in the Drawing opposite to the
object glass are not used when the telescope is intended for land purposes.
a is the body; b, the draw or focussing slide; c, the object glass; e, f, and g, are
ordinary light stops; h is the field. glass; i, the eye-glass; and k, the transparent
diaphragm, the surface of which is placed exactly in the focus of the eye-glass i,
[Price 6d.]
'

page_text: .
so that the scale thereon may be read distinctly while viewing the object. The
whole is so arranged that the image formed by the object glass c falls exactly on
the surface on which the scale is engraved, photographed, or formed. is a collar
fitting on the end of the object glass end of the telescope, carrying a bracket m,
which supports two plain reflectors n, n, placed at proper angles a short distance
from the object glass. These reflectors reach only to the axial line of the telescope,
leaving half the area of the object glass to receive the direct rays of light and half
to receive the lateral rays of light. These reflectors are only used, as already
explained, when the telescope is used for ascertaining distances at sea where the
object is between the telescope and visible land.
The apparatus illustrated may be arranged for the use of infantry and artillery,
and it is believed that by its aid time-fuse shrapnell may be immediately fired,
because the first shot will come near enough to the mark aimed at to permit of
subsequent corrections. At present this is not possible, because the cloud caused by
the explosion of the shrapnell shot is formed in the air, and its position with regard
to the object aimed at can only be judged of when the object appears immediately
above or below the cloud, hence several trial shots have to be fired with the per-
cussive grenade, the effect of which is comparatively small before the firing with
time-fuse shrapnell is commenced.
i
With the improved telescope forming the subject of this Invention only about
one-third of a minute is on an average required to measure a distance. The
successful results attained, and the extraordinary rapidity and convenience with.
which the instrument may be used; are due to a new application of an old principle.
The average height of a full grown man differs as a rule only by a small percentage
from a certain measure, for which my foreign correspondent has adopted 1.75 metres.
For a man who is ten per cent. smaller is so much of a dwarf as not to be met with
amongst the military. The danger of being led astray by the opposite extreme is
also very small, because one has generally the choice between several objects. In
the telescope illustrated will be seen the image magnitudes that belong to 1.75
metres for the distances 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210,
220, 230, 240, 250, 260, 270, 280, 290, 300, 350, 400, 450, 500, 600, 700, 800, 900,
1,000, 1,100, etc. up to 3,000 metres; these are given as the ordinates of an equi-
lateral hyperbola, whilst the abscissae represent the distances. For the product of
the image magnitude into the distance is constant. The small variations caused by
the focussing play no perceptible part. In order to measure the distance of a man
standing or walking in an upright position, one proceeds as follows:-If the
distance is 500 metres or more his feet must be brought into contact with the
axis of the abscissae, which is divided into equal parts, and which must he held in a
horizontal position, at the same time his head must touch the hyperbola; the corre-
If the
sponding abscissa must be read off below, and gives the distance in metres.
distance is less than 500 metres, then to obtain greater accuracy the man must be
placed between the axis of the abscissae, and a straight line (x, Fig. 5) running
parallel to the same, so that the soles of his feet are in contact with the former, and
the crown of his head with the latter. The latter (viz., the horizontal line x,
parallel to the axis of the abscissae) leads to a number on the axis of the ordinates,
which is divided into unequal parts, which number represents the distance.
It is to be observed that the hind quarters of a horse from his hoofs to his spine
are also about 1.75 metres high.
In Fig. 5 I have laid down the hyperbola in as far as it is applicable for a man
on horseback (height 2.75 metres). The very thick lines are merely marks for the
photographer to enable him to obtain the right size. The application of the hyper-
bola contributes essentially to the successful result.
When applying this Invention in the form of a marine distance measurer a ball-
and-socket joint is interposed between the telescope and its stand, the socket being
secured by means of a wood screw, 20 metres, or according to circumstances at
any other height above the surface of the water, and the rocking motion (which has
little effect ou the height) must be followed by hand until the sea horizon is brought

page_text: into coincidence with a line appropriately marked on the transparent diaphragm.
The place at which the water-line of a distant ship appears then gives the distance
with comparatively great accuracy. A system of 10 hyperbolas is employed, between
which one can mentally interpolate others at pleasure, to be designated 0.1, 0.2, 0.3,
etc., and the said hyperbolas play the following important part :-When the distance
has been found by the above method one puts a well bounded, otherwise arbitrary
[vertical], line belonging to the observed ship into the system of hyperbolas, making
its image magnitude the ordinate corresponding to the abscissae representing the
distance, e.g. if the ordinate for the hyperbola were 8.6 (i.e. for that point of a
hyperbola which lies rather nearer to that of hyperbola 9 than to hyperbola 8) then
one has subsequently only to bring the same line or dimension, say the length of a
mast, into a position at right angles to the axis of abscissae, so that one end falls
upon this axis, and the other upon the hyperbola 8.6, in order to obtain the
distance from any place at any time. One can thus abandon the elevated position.
In a squadron the most suitable ship could effect the introductory measurement,
and for any preconcerted dimension could signal the hyperbola to her consorts.
It remains to explain the use of the two mirrors. Not unfrequently it will
happen that land is in the background of the enemy's ship, then it is still neces-
sary to find the position of the sea horizon. By rotating the telescope about its
optical [longitudinal] axis, the images of the horizon which are reflected right and
left from behind must be brought into one and the same line. In anticipation of
the case mentioned, the mirrors must be so adjusted on the open sea that the
direct and reflected double horizons coincide. The reflected horizon then supplies
the place of the actual horizon, and the measure can be made just as if one saw
the horizon directly.
As far as concerns the distance measurer, the left half of the field of view con-
sists of a system of horizontal lines numbered according to the distance in metres,
and this distance is obtained by the use of a vertical base of suitable magnitude on
the ship of the observer from the angular interval between the water-line of the
enemy's ship and the sea horizon.
As soon as the distance is found on the left half of the field of view, the system
of hyperbolas in the other half serves to designate a base (which must also be
vertical and visible from the allied vessels) on the enemy's ship; the image
magnitude of this baso, as it presents itself to the other ships, is the ordinate of a
hyperbola, while the abscissa is the distance. After the base has been thus trans-
ferred to the enemy's vessel, the distance can be measured without any further
trouble at each moment with the greatest rapidity and ease.
For rapid surveys the small distance measurer may be combined with a pris-
matic compass; with these one circles around any object visible in every direction,
e.g., the spire of a tower. On this any arbitrary dimension is chosen. The actual
scale of the plan laid down is found afterwards by measuring a single line.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Lloyd Wise in the Great Seal Patent Office on the 27th
December 1876.
sex.
WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the County of Middle-
"IMPROVEMENTS IN TELESCOPES WHEREBY THEY ARE RENDERED AVAILABLE
FOR MEASURING DISTANCES." A communication from abroad by Wilhelm
Klinkerfues, Professor and Director of the Royal Observatory at Göttingen, Hanover.
This Invention has for its object improvements in telescopes whereby they are
rendered available for measuring distances.
For this purpose, in combination with the lenses of the ordinary telescope, I
use a transparent diaphragm, having marked thereon a scale, arranged as herein-
after described.

page_text: In telescopes according to this Invention for nautical purposes I also employ
mirrors, as herein-after mentioned, for obtaining an artificial horizon.
To enable the nature of the Invention to be more readily understood I append
a Sheet of Drawings, shewing one arrangement of telescope, but I desire it to be
understood that the Invention is not limited to the precise arrangement illustrated.
Fig. 1 is a central vertical section; Fig. 2 is a plan; Fig. 3 is an end view of
the transparent diaphragm.
Fig. 4 is an end view of the telescope looking towards the object glass.
Fig. 5 is an enlarged view illustrating the general arrangement of the scale as
used for land purposes.
It is to be understood that the mirrors shewn in the Drawing opposite to the
object glass are not used when the telescope is intended for land purposes.
a is the body; b, the draw or focussing slide; c, the object glass; e, f, and g, are
ordinary light stops; h, is the field glass; i, the eye-glass; and k, the transparent
diaphragm, the surface of which is placed exactly in the focus of the eye-glass i,
so that the scale thereon may be read distinctly while viewing the object. The
whole is so arranged that the image formed by the object glass c falls exactly on
the surface on which the scale is engraved, photographed, or formed. is a collar
fitting on the end of the object glass end of the telescope, carrying a bracket m,
which supports two plain reflectors n, n, placed at proper angles a short distance
from the object glass. These reflectors reach only to the axial line of the telescope,
leaving half the area of the object glass to receive the direct rays of light and half
to receive the lateral rays of light. . These reflectors are only used, as already
explained, when the telescope is used for ascertaining distances at sea where the
object is between the telescope and visible land.
The apparatus illustrated may be arranged for the use of infantry and artillery,
and it is believed that by its aid time-fuse shrapnel may be immediately fired,
because the first shot will come near enough to the mark aimed at to perinit of
subsequent corrections. At present this is not possible, because the cloud cause
by the explosion of the shrapnel shot is formed in the air, and its position with
regard to the object aimed at can only be judged of when the object appears imme-
diately above or below the cloud, hence several trial shots have to be fired with
the percussive grenade, the effect of which is comparatively small before the firing
with time-fuse shrapnel is commenced.
With the improved telescope forming the subject of this Invention only about
The
one-third of a minute is on an average required to measure a distance.
successful results attained, and the extraordinary rapidity and convenience with
which the instrument may be used, are due to a new application of an old principle.
The average height of a full grown man differs as a rule only by a small percentage
from a certain measure, for which my foreign correspondent has adopted 175
metres. For a man who is ten per cent. smaller is so much of a dwarf as not to
be met with amongst the military. The danger of being led astray by the opposite
extreme is also very small, because one has generally the choice between several
objects. In the telescope illustrated will be seen the image magnitudes that
belong to 1.75 metres for the distances 100, 110, 120, 130, 140, 150, 160, 170, 180,
190, 200, 210, 220, 230, 240, 250, 200, 270, 280, 290, 300, 350, 400, 450, 500, 600,
700, 800, 900, 1,000, 1,100, etc. up to 3,000 metres; these are given as the ordinates
of an equilateral hyperbola, whilst the abscissae represent the distances. For the
product of the image magnitude into the distance is constant. The small vari-
ations caused by the focussing play no perceptible part. In order to measure the
distance of a man standing or walking in an upright position one proceeds as
follows: If the distance is 500 metres or more his feet must be brought into
contact with the axis of the abscissae, which is divided into equal parts, and which
must be held in a horizontal position, at the same time his head must touch the
hyperbola, the corresponding abscissa must be read off below, and gives the distance
in metres. If the distance is less than 500 metres, then to obtain greater accuracy
the man must be placed between the axis of the abscissue, and a straight line

page_text: (x, Fig. 5) running parallel to the same, so that the soles of his feet are in contact
with the former, and the crown of his head with the latter. The latter (viz., the
horizontal line x, parallel to the axis of the abscissae) leads to a number on the
axis of the ordinates, which is divided into unequal parts, which number repre-
sents the distance.
It is to be observed that the hind quarters of a horse from his hoofs to his spine
are also about 1.75 metres high.
In Fig. 5 I have laid down the hyperbola in as far as it is applicable for a man
on horseback (height 2.75 metres). The very thick lines are merely marks for
the photographer to enable him to obtain the right size. The application of the
hyperbola contributes essentially to the successful result.
When applying this Invention in the form of a marine distance measurer a ball-
and-socket joint is interposed between the telescope and its stand, the socket being
secured by means of a wood screw 20 metres, or according to circumstances at any
other height above the surface of the water, and the rocking motion (which has
little effect on the height) must be followed by hand until the sea horizon is brought
into coincidence with a line appropriately marked on the transparent diaphragm.
The place at which the water-line of a distant ship appears then gives the distance
with comparatively great accuracy. A system of 10 hyperbolas is employed, between
which one can mentally interpolate others at pleasure, to be designated 0.1, 0.2,
0.3, etc., and the said hyperbolas play the following important part -When the
distance has been found by the above method one puts a well bounded, otherwise
arbitrary [vertical], line belonging to the observed ship into the system of hyper-
bolas, making its image magnitude the ordinate corresponding to the abscissae
representing the distance, e.g. if the ordinate for the hyperbola were 8.6 (i.e. for
that point of a hyperbola which lies rather nearer to that of hyperbola 9 than to
hyperbola 8) then one has subsequently only to bring the same line or dimension,
say the length of a mast, into a position at right angles to the axis of abscissae, so
that one end falls upon this axis, and the other upon the hyperbola 86, in order to
obtain the distance from any place at any time. One can thus abandon the
elevated position. In a squadron the most suitable ship could effect the introductory
measurement, and for any preconcerted dimension could signal the hyperbola to her
consorts.
It remains to explain the use of the two mirrors. Not unfrequently it will
happen that land is in the back ground of the enemy's ship, then it is still necessary
to find the position of the sea horizon. By rotating the telescope about its optical
[longitudinal] axis, the images of the "horizon which are reflected right and left from
behind must be brought into one and the same line. In anticipation of the case
mentioned the mirrors must be so adjusted on the open sea that the direct and
reflected double horizons coincide. The reflected horizon then supplies the place of
the actual horizon, and the measure can be made just as if one saw the horizon
directly.
As far as concerns the distance measurer, the left half of the field of view consists
of a system of horizontal lines numbered according to the distance in metres, and
this distance is obtained by the use of a vertical base of suitable magnitude on the
ship of the observer from the angular interval between the water-line of the enemy's
ship and the sea horizon.
As soon as the distance is found on the left half of the field of view, the system of
hyperbolas in the other half serves to designate a base (which must also be vertical
and visible from the allied vessels) on the enemy's ship; the image magnitude of
this base as it presents itself to the other ships is the ordinate of an hyperbola,
while the abscissa is the distance. After the base has been thus transferred to the
enemy's vessel, the distance can be measured without any further trouble at each
moment with the greatest rapidity and ease.
For rapid surveys the small distance measurer may be combined with a prismatic
compass; with these one circles around any object visible in every driection, e. g. the

page_text: spire of a tower. On this any arbitrary dimension is chosen. The actual scale of
the plan laid down is found afterwards by measuring a single line.
As is well known a metre, which my foreign correspondent has chosen as the
standard of measurement, equals 3937 English inches.
Having described the nature of the said Invention, and the manner of carrying
the same into practical effect as communicated to me as aforesaid, I hereby declare
that what I consider to be novel and original, and claim as the Invention secured to
me by the herein-before in part recited Letters Patent, is-
First. As an improvement in telescopes; the combination with the body a, object
glass c, light stops e, f, and g, field glass h, and eye-glass i of a transparent diaphragm
(k) having engraved, photographed, or formed thereon a scale in which the image-
magnitudes are given as the ordinates of an equilateral hyperbola, and the abscissae
represent the distances as described, the surface of the said transparent diaphragm
being placed exactly in the focus of the eye-glass i, so that the scale thereon may be
read distinctly while viewing the object, the whole being so arranged that the image
formed. by the object glass c falls exactly on the surface on which the scale is
engraved, photographed, or formed, as herein set forth for the purpose specified.
Secondly. The combination with the parts enumerated in the preceding claim of
the collar fitting on the object glass end of the telescope, the bracket m and the
two plain reflectors n, n, arranged angularly a short distance from the object glass,
as described, and made to reach only to the axial line of the telescope, thus leaving
half the area of the object glass to receive the direct rays of light and half to receive
the lateral rays of light, all substantially as herein'set forth and shewn for the pur-
pose specified.
In witness whereof, I, the said William Lloyd Wise, have hereunto set my hand
and seal, this Twenty-seventh day of December, in the year of our Lord One
inht hundred and gaventy-six
Witness,
F. J. BROUGHAM.
W. LLOYD WISE. (L.S.)