Improvements in Range and Position Finders.
Year: 1897

page_text: Date of Application, 30th Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in Range and Position Finders.
A communication from ISAAC NEWTON LEWIS, of Fort Wadsworth, County of
Richmond, State of New York, United States of America, First Lieutenant
in the United States Army.
I, WILLIAM LLOYD WISE, of 40, Lincoln's Inn Fields, in the County of London,
Consulting Engineer and Chartered Patent Agent, do hereby declare the nature
of this invention to be as follows:-
This invention relates to range and position finders intended for use in coast
defense. It particularly relates to that class of these instruments which operate
upon a vertical base.
Range and position finders of this class are particularly well adapted for coast
defense, since by one of these instruments a single operator can accurately and
immediately locate an object at sea and readily follow its course, the instrument
being so constructed and provided with quick reading devices that the successive
positions of such object may be read at a glance.
One object of this invention is to construct quick reading devices for this class
of instruments which will dispense with verniers, give more accurate readings,
and which may be read in much less time.
Another object of the invention is to so construct said quick-reading devices and
so associate them with the other parts of the range and position finder that they
will be actuated in the routine operation of the instrument and show the absolute
position of the object the instant the instrument is brought to rest.
With these objects in view the invention consists in the construction, combina-
tion and arrangement of parts hereinafter fully described and set forth in the
claims.
In the accompanying drawings which form a part of this specification
Fig. 1, represents in partially sectionized side elevation a
position finder embodying this invention.
range and
Fig. 2, represents in plan, the traversing arm of this instrument, the telescope
being removed.
Fig. 3, is an elevation of the rear end of the instrument, the pedestal being
omitted.
Fig. 4, is a detail of one of the parts of said instrument.
Fig. 5, is a rear view of the quick reading device for giving the azimuth of an
object.
Fig. 6, is a plan of said device.
Fig. 7, represents in vertical section and under-side plan an adjustment attach-
ment for the azimuth indicator.
Fig. 8, is a diagram explaining the problem of obtaining the range of an object
by a range finder operating on a vertical base.
Fig. 9, is a partially sectionized side elevation of a range and position finder
embodying this invention.
Fio 10 is a plan of the same.

page_text: Fig. 11, is a vertical section taken in the plane represented by line 11, 11, Fig. 1.
Fig. 12, is a vertical section through the quick reading azimuth device.
Before proceeding to a detail description of this instrument and its operation,
it is deemed best to call attention to the fact that in range finders having a vertical
base the location of an object is always a problem in right angle triangulation.
The height of the pivotal point of the instrument's telescope above sea level is
the base of triangulation for all azimuths taken from that position of the instru-
ment and it is the vertical of the right angle triangle of every range observation.
The range of the object observed is the horizontal of said triangle. The line of
collimation of the instrument when establishing the range of an object is the
hypothenuse of the triangle and the angle between this and the horizontal is the
angle of depression through which the telescope of the instrument is moved in
directing it upon the object.
One form of the instrument illustrated for carrying out the objects of this inven-
tion (see Figs. 1-7,) has a pedestal A, provided with suitable leveling screws B,
a circular table C, planed perfectly smooth on top and edge and mounted upon the
pedestal, and a traversing arm D), which carries the telescope E, and the mechanism
for manipulating it and for indicating the various positions in which it may be
moved.
The traversing arm may be of any desired form but by preference it has its
forward end elevated in a manner to leave a clear space between it and the table
substantially as shown. In the forward end of this arm, on suitable trunnions,
is mounted the frame which carries the telescope and the rear end of the arm is
flattened horizontally to furnish a platform for the support of the manipulating
devices of the instrument and the quick reading devices or indicators.
To provide for a free movement of the traversing arm a female center F, is
mounted in the table and depends into the pedestal. This center, as shown, is
contracted downwardly and at its lower end provided with an adjusting screw G,
upon which rests the male center H, which is rigidly secured to the traversing arm
and tapered to correspond to the female center. By the movement of screw G,
the friction between the parts F and H, may be varied and the free movement of
the traversing arm regulated. Two other points of support for the arm D), are
furnished by means of the rollers I, which are mounted on the platform of said
arm and roll upon the table C.
The
The traversing arm may be rotated about its center by any suitable means.
means illustrated consists of a friction roller J, mounted on the arm D, and bearing
upon the edge of the table C. This roller is by preference mounted as shown in
detail in Fig. 4, wherein a bracket J', is constructed for attachment to the under-
side of the said arm, Figs. 1 and 3. In this bracket, by means of lateral
trunnions J2, is pivoted a frame J3, and in this the roller J, is journalled. This
manner of mounting the roller insures an even bearing thereof for its entire length
upon the edge of the table. The lower journal of the roller is extended through
the frame and upon it is fixed the bevel gear K. Meshing with this gear is the
bevel pinion K¹, and this is carried on the shaft K2, which is journalled in brackets
depending from the arm D. The outer end of the shaft K³, is provided with a
crank for rapid movement and with a milled head K³, for slight rotation of the
shaft in obtaining fine adjustment. It will be seen that by the rotation of the
shaft K2, the traversing arm may be rotated upon its center H. Obviously instead
of the friction roller and bevel gear, a spur gear might be cut on the edge of the
table and a pinion to mesh therewith substituted for the bevel pinion K¹.
The rotation of the traversing arm is for the purpose of obtaining the azimuth
of an object.
Various means may be adopted for indicating the azimuth. The one here shown
is of the quick reading sort and is operated as the arm is rotated. This device has
a vertical shaft L, mounted in the platform of arm D, and provided with a friction
roller L, which engages with the edge of the table C. By this means rotation is
imparted to the shaft L. This shaft transmits motion to the scales or indicators

page_text: of the quick-reading azimuth device. For this purpose the shaft L, has a worm M,
cut thereon with which meshes a worm wheel N, for the rotation of the degree
scale O, which is located in the casing O¹, and which displays its graduations
through an opening in the face of the casing, as seen in Fig. 3. Minutes of aro
are indicated by a disc P, located in the casing P1, and rotated through a train of
multiplying gearing consisting of the gear Q, on the shaft L, and the pinion Q, in
mesh therewith and mounted on the same shaft as the scale P. The graduations
of the scale P, are displayed through an opening in the face of casing P¹, as seen
in Figs. 2 and 6. The pitch lines of the aforesaid gears, where seen in plan, are
represented by broken lines.
In order to place the traversing arm and these scales at an initial or zero
position the friction wheel L', is adjustably mounted upon the shaft L. This
adjustment may be made in any suitable manner; one way of accomplishing it,
illustrated in Fig. 2, consists in making wheel L', movable about shaft L, provid-
ing said shaft with a conical nut L³, and a milled head, and in attaching a flexible
disc L³, to the face of wheel L', by screws which may clamp the conical nut between
the wheel and disc thereby fixing the wheel against rotation upon the shaft. To
adjust the azimuth scale to correspond with the zero position of the traversing arm
it is then only necessary to loosen the screws in disc L³, give shaft L, the necessary
rotation by means of the milled head and then tighten said screws
The rear end of the telescope is supported upon a vertically movable column R,
guided in the bracket R¹, which is mounted upon the traversing arm. On the upper
end of this column is preferably mounted a grooved roller R³, upon which rests a
pin S, projecting from one of the cross-pieces of the telescope frame or support.
For raising the column a rack is formed upon it with which meshes a sector gear T.
This sector is journalled in a stand T", and is provided with an arm or lever T, by
which its movement is controlled.
Upon this platform of the traversing arm at the side of this stand is erected a
support U, in which is journalled a vertical screw U¹. Upon this screw is a nut
which carries a transverse slotted plate U. Along the upper edge of this slot is
located a scale and in the slot is a nut U³, threaded upon a screw U', which, in any
suitable manner, is fixed against endwise movement in said plate. This screw is
provided with a milled head and as it is turned the nut U³, moves through the.
slot to any desired position on the scale. Upon the face of the nut U³, is mounted
a small roller against which the arm T², bears.
To rotate the screw U₁, and so raise or lower the plate U2, a bevel gear as at V,
may be employed, one pinion of which is upon the screw U¹, while the other is
upon a horizontal shaft carrying the crank V₁. For fine adjustments, may be
used the milled head V2, mounted with the crank upon this shaft.
The effect of the rotation of the screw U₁, and therefore the change in the eleva-
tion of the eye-piece of the telescope may be indicated by means of a disc as W, which
is journalled on a stud depending from the platform of the arm D, and is provided
with a toothed edge with which meshes the pinion W₁, mounted on the lower end
of the screw shaft U¹. The edge of this disc projects beyond the platform of arm D,
and is housed by casing W2, through an opening in which its graduation may be
read. This casing W2, is omitted in Fig. 3.
It is only necessary that such a portion of the weight of the telescope shall be
borne by the column R, and therefore by the arm 1, as will keep said arm in
intimate contact with the roller carried by nut U³, therefore the telescope is suit-
ably counterweighted as by weights located in the columns X, and joined to the
telescope supporting frame as by flexible connections X', which pass over suitable
pulleys on the top of said columns.
It will be seen then, by referring particularly to Fig. 3, that any rotation of the
screw U+, will affect the elevation of the eye-piece of the telescope and the rotation
of the screw U¹, will also affect the elevation of the eye-piece of the telescope and
at the same time rotate the indicator disc W, from which may be read the range of
the object sighted, the ranges, within the capacity of the instrument, having,

page_text: been computed for the various angles of depression, to which the telescope is
adapted, and marked upon the disc W. As the ranges vary unequally for successive
equal angles of depression, the scale is one of unequal graduation.
Each instrument is constructed to operate accurately at the elevations between
certain limits and for certain ranges. The adjustment of an instrument to a certain
altitude, or in other words to a certain vertical base, is effected by moving nut U³,
to the graduations upon its scale which corresponds to that particular base, said
scale having been plotted to correspond to the possible changes of base within the
capacity of the instrument. This scale on plate Us, may therefore be termed the
altitude scale.
Any movement of the nut U³, produces through the parts T, T and R, a move-
ment in the telescope corresponding to the change of base indicated upon said scale.
A change of base through a change in location of the instrument must be corrected
for by moving this nut. Mean low-tide is taken as the initial point in reckoning
the working base, and any change in tide must be corrected for by moving this nut
the predetermined amount corresponding thereto.
In making observations the various ranges may if desired be plotted by means
of a suitable marker Y, movably mounted upon scales as Y', attached at one end
to the hub of arm I), and at the other to a bracket as Z, depending from said arm.
Paper being spread upon the table C, it only remains, when the range of an object
is determined, to move the marker to the point on the scale corresponding to the
range found and press it down onto the paper. Radial lines drawn from the center
of table C, will show the azimuths of the objects whose ranges are plotted.
For leveling the instrument, a suitable spirit level may be mounted as at &, upon
the arm D. Then by moving the arm first into the plane of one and then of another
leg of the pedestal A, and working the screws B, the instrument is speedily brought
to the proper position.
Before detailing the operation of the instrument it may be well to refer to the
diagram Fig. 8, and point out the difficulties in the way of a vertical base range
finder and how this invention overcomes such difficulties.
Let the heavy short line E, represent the telescope, e, its pivotal point, a, c,
the elevation of said point above mean low-tide, a, b, the apparent level of the
water, a, d, the true surface of the water, and c, e, a horizontal line through the
pivotal point of the telescope. Then were the telescope turned on an object at b,
the line of collimation would be c, b, and the right angle triangle c, a, b. The angle
of depression of the telescope would then he c, c, b, to which the angle e, b, a, is
equal. Then knowing the latter angle the horizontal distance or range of the object
at b, can be readily computed.
But an object in the water at the distance a, b, would on account of the curvature
of the earth, be at a point below b, as at d. To reach this object a greater
depression of the telescope is necessary but in effecting this depression the line of
collimation cuts the line a, b, as at r, and in computing the range of the object
from the new angle of depression e, c, d, and the base a, c, an erroneous range a, i,
would be obtained.
The distance of any point on the curve a, d, below the tangent a, b, is known
and an allowance on account thereof for each unit of range may be made on the
range scale W, in the construction of the machine, so that when an object is
sighted as at , the true base for that range is the sum of the base a, c, and the
distance (b. d) which that object is below the tangent a, b, (or c, f,). The true
range f,, is then readily obtainable.
In making this correction for curvature of the earth account must be taken of
refraction of the atmosphere which has the effect of elevating the object above its
true position. This effect, under normal atmospheric conditions is found to be
about one-seventh the effect of curvature. This correction for mean refraction
being, on account of a permanent condition, for all ranges within the capacity of
a certain instrument, is in the construction of the instrument computed for each
unit of range indicated upon the scale W.

page_text: There are still two corrections which must be made for variable conditions such
as the rise and fall of tides and abnormal refraction. These corrections must be
made by adjustments in the instrument and will be brought out in describing the
operation of the instrument.
The instrument is set up and adjusted by means of screw U*, so that its working
base equals its altitude above mean low-tide. Then, when an observation is to be taken,
the reading from a tide gage is obtained and the nut Us, moved along to a point on
the scale of plate U2, corresponding to the working base for that particular height
of tide. This movement shifts the telescope into position for all ranges within
the scope of the instrument at that height of tide.
Then to correct for abnormal refraction the instrument may be set for the range
of some known object and if by turning it upon that object the horizontal cross-
hair of the telescope does not coincide with the water line thereof, the cross-hair
must be adjusted until such coincidence is effected. This is done by turning a
screw as E, which controls the position of said cross-hair, the cross hair being
mounted in a vertically adjustable frame in the well known manner.
The instrument having been brought into consonance with the prevailing con-
ditions, the traversing arm is then moved in azimuth by the rotation of shaft K²,
until the telescope points in the direction of the object whose range is to be
determined. Then by turning the crank V, or head V2, the telescope will be
tilted until the horizontal cross-hair coincides with the water line of the object.
The range may be then immediately read directly from the scale W, in yards and the
azimuth read directly from the scales 0 and 1, in degrees and minutes respectively.
So rapidly can the parts of the instrument be manipulated that an object within
the field of the instrument may be accurately located in less than ten seconds and
if desired the course of a moving object may be plotted by points at intervals of
ten seconds.
It will be noted that the range and direction scales are operated by those move-
ments of the instrument by which an object is located and that as soon as the
object is located the readings may be directly taken from the scales without calcu-
lation of any sort. This is important as it enables any man of ordinary intelligence
to operate the instrument. It is also to be noted that the scales are operated through
trains of multiplying gear from parts of the instrument necessarily moved in locat-
ing an object, and that in the azimuth indicating device the table of the instrument
is in reality the motor gearing of the train operating the degree and minute scales.
These constructions give instantaneous and accurate indications and dispense with
all forms of verniers.
The instrument as above described is adapted to be moved from one location to
another but is intended more especially for use at some fixed place, while the instru-
ment in the modified form illustrated in Figs. 9-12, is of lighter construction and
especially designed for shifting from one location to another.
At such locations may be formed a base or foundation 13, of concrete or other
suitable material in which a pedestal 14, is secured. This pedestal may be pro-
vided with any suitable means for attaching the stand of the instrument thereto,
the one shown consisting of a screw-threaded stud 15. The lower end of said
stand may consist of a plate or spider 16, near the outer periphery of which suit-
able depressions may be made for the reception of leveling screws 17, which turn
in arms 18, formed upon the upper part of the stand 19. In the center of the
part 19, is located a cylindrical female center 20, which is secured in place by
any suitable means as the set screw 21. This center has formed upon its lower
end an enlargement which with the contracted upper end of the center portions
of plate 16, constitutes a ball and socket joint by which the upper portion of the
stand is allowed freedom of movement in all directions for the sake of adjustment.
Through the female center 20, is passed the male center 22, which has a flange at
its upper end resting upon the top of the center 20, and a nut upon its lower end
turned against the lower end of the center 20. In this way all the parts of the
stand are held together and yet allowance is made for the necessary adjustments.

page_text: The upper end of the center 22, is screw-threaded and passes through the table 23,
into the rib 24, which is provided with a hub at its middle for the reception of said
center and is secured in place diametrically across the table. This rib projects
upwardly at the forward end and has pivoted thereto at 25, the telescope support 26,
in which the telescope E, is mounted in any suitable way, as by the bands shown.
A spirit level as &, is mounted upon the rib 24, and by turning the table so as to
bring said rib successively over the different adjusting screws of the stand the
instrument may be accurately levelled.
Upon the stand there is secured a circular rack or toothed plate 27, with which
meshes a pinion 28, which may be rotated by any suitable means as by a milled
head 281, located on the surface of the table 23. By means of this screw the
table may be moved for fine adjustment but the rotation thereof for any consider-
able distance may be done by taking directly hold of the table.
By means of the parts just described the telescope may be moved in azimuth
upon any object. Various means may be adopted for determining the azimuth of
any object upon which the telescope is brought to bear. A quick-reading device for
this purpose is preferred, one form of which is illustrated in Figs. 10 and 12. This
device consists of the toothed plate 27, a pinion 36, which meshes with the toothed
plate 27, and is mounted upon a shaft located within the casing 29, mounted upon
the table 23; the gear 37, on the upper end of said shaft; the pinion 38, with
which gear 37, meshes; the pointer 39, mounted upon the shaft with pinion 38;
and the dial graduated to minutes of arc over which the pointer moves.
The degree
scale is marked upon the plate 27, and appears through 'an opening in the table
as at 40. This circular plate 27, serves as the motor gear of the quick reading
device. When the table has been moved to bring the telescope into a particular
direction the azimuth of the object sighted may be read immediately in degrees
and minutes from the indicator just described.
As above stated the pivotal point of support for the telescope is at 25. To raise
and lower the eye-piece of the telescope, a screw as 30, is mounted in the rear end
of the rib 24, and turned by means of the milled projection 301. Upon this screw
within an enlargement of the rear end of said rib is located a nut as 31, which is
capable of vertical movement in its support and is prevented from rotary movement
by a suitable feather indicated in dotted lines at 31. A slight groove is cut longi-
tudinally of the upper surface of this nut and in this groove rests the conical end
of an adjusting screw 32, which is also provided with a milled projection for turn-
ing it. This screw turns through a nut 32', mounted within a casing secured to
the rear end of the support 26. This casing is so constructed that a portion of the
nut projects through a slot in the side thereof and bears a line pointing to the
scale 32, marked upon the outside of said casing. Provision is also made for
movement of this nut longitudinally of the casing and such movement produced
by means of the screw 33, which is secured against longitudinal movement in the
casing and provided with a milled head as shown. These three screws 30, 32 and
33, provide for the vertical movement of the eye piece of the telescope for special
purposes hereinafter specified.
Any rotation of the screw 30, to move the telescope also actuates the range
scale 34, which consists of a circular toothed plate mounted to rotate upon the
stand 19, between the table and the plate 27. The graduations of this scale show
through an opening in the table 23, as at 35.
After this instrument is placed upon its pedestal and levelled up, the altitude
of the pivoted center of the telescope above low mean tide is obtained from any
suitable instrument, then the screw 33, is rotated to place the point of screw 32,
at such a position upon the nut 31, as will make the working base of the instru-
ment or the vertical of the right angle triangle for the observations from that
station equal to the altitude of the instrument. Then, when an observation is to
be taken, this working base is corrected for the condition of the tide by first
obtaining the height of tide from any suitable tide-gauge, and then turning
the screw 33, to place the screw 32, in alignment with that degree of scale 32

page_text: which corresponds to the vertical base with the tide at the height observed, the
scale 32, having in the construction of the machine been plotted for the adjustment
of altitude and correction for tide. This correction for tide shifts the telescope
into position for all ranges within the scope of the instrument at that height of
tide. Then correction must be made for abnormal refraction. To do this the
instrument may be set for the range of some known object and if by turning it
upon that object the horizontal cross-hair of the telescope does not coincide with
the water line thereof, the eye-niece of the telescope must be raised or lowered
until such coincidence is effected. This is done in this form of instrument by
turning the screw 32. By using the screw 32, for this purpose, the delicate micro-
meter adjustment employed for shifting the cross-hair of the telescope in the other
form of instrument may be dispensed with.
The instrument having been corrected for tide and abnormal refraction, the
table is moved in azimuth, as above described, until the telescope points in the
direction of the object whose range is to be determined, then by turning the screw 30,
the telescope may be tilted until its horizontal cross-hair coincides with the water
line of the object. The range may be then immediately read directly from the
scale 34, in yards, and the azimuth read directly from the indicators 39 and 40,
in degrees and minutes.
It will be noted that in this form of the instrument also the direction or azimuth
indicator is operated by the movement of the instrument by which an object is
located, and that the range is also indicated by such movement so that as soon as
the object is located the readings may be directly taken from the scales without
correction or computation of any sort and without the use of verniers.
Many changes may be made in the form, construction and combination of parts
of the instrument aside from those above described without departing from the
spirit of the invention.
Date : ou 1
P
1004
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
A communication from ISAAC NEWTON LEWIS, of Fort Wadsworth, County of
Richmond, State of New York, United States of America, First Lieutenant
in the United States Army.
I, WILLIAM LLOYD WISE, of 46, Lincoln's Inn Fields, in the County of London,
Consulting Engineer and Chartered Patent Agent, 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 range and position finders intended for use in coast
defense. It particularly relates to that class of these instruments which operate
upon a vertical base.
Range and position finders of this class are particularly well adapted for coast
defense, since by one of these instruments a single operator can accurately and
immediately locate an object at sea and readily follow its course, the instrument
being so constructed and provided with quick reading devices that the successive
positions of such object may be read at a glance.
One object of this invention is to construct quick reading devices for this class

page_text: of instruments which will dispense with verniers, give more accurate readings, and
which may be read in much less time.
Another object of the invention is to so construct said quick-reading devices and
so associate them with the other parts of the range and position finder that they
will be actuated in the routine operation of the instrument and show the absolute
position of the object the instant the instrument is brought to rest.
With these objects in view the invention consists in the construction, combina-
tion and arrangement of parts hereinafter fully described and set forth in the
claims.
In the drawings filed with my Provisional Specification:-
Fig. 1, represents in partially sectionized side elevation a range and position
finder embodying this invention. Fig. 2, represents in plan, the traversing arm
of this instrument, the telescope being removed. Fig. 3, is an elevation of the
rear end of the instrument, the pedestal being omitted. Fig. 4, is a detail of one
of the parts of said instrument. Fig. 5, is a rear view of the quick-reading
device for giving the azimuth of an object. Fig. 6, is a plan of said device. Fig. 7,
represents in vertical section and underside plan an adjustment attachment for
the azimuth indicator. Fig. 8, is a diagram explaining the problem of obtaining
the range of an object by a range finder operating on a vertical base. Fig. 9, is a
partially sectionized side elevation of a range and position finder embodying a
modification of this invention. Fig. 10, is a plan of the same. Fig. 11, is a vertical
section taken in the plane represented by line 11, 11, Fig. 9. Fig. 12, is a vertical
section through the quick-reading azimuth device.
Before proceeding to a detail description of this instrument and its operation, it
is deemed best to call attention to the fact that in range finders having a vertical
base the location of an object is always a problem in right angle triangulation. The
height of the pivotal point of the instrument's telescope above sea level is the base
of triangulation for all azimuths taken from that position of the instrument and it
is the vertical of the right angle triangle of every range observation. The range of
the object observed is the horizontal of said triangle. The line of collimation of
the instrument when establishing the range of an object is the hypothenuse of the
triangle and the angle between this and the horizontal is the angle of depression
through which the telescope of the instrument is moved in directing it upon the
object.
One form of the instrument illustrated for carrying out the objects of this inven-
tion (see Figs. 1-7) has a pedestal A, provided with suitable leveling screws B,
a circular table C, planed perfectly smooth on top and edge and mounted upon the
pedestal, and a traversing arm D, which carries the telescope E, and the mechanism
for manipulating it and for indicating the various positions in which it may be
moved.
The traversing arm may be of any desired form but by preference it has its
forward end elevated in a manner to leave a clear space between it and the table
substantially as shown. In the forward end of this arm, on suitable trunnions, is
mounted the frame which carries the telescope and the rear end of the arm is
flattened horizontally to furnish a platform for the support of the manipulating
devices of the instrument and the quick-reading devices or indicators.
To provide for a free movement of the traversing arm a female center F, is
mounted in the table and depends into the pedestal. This center, as shown, is con-
tracted downwardly and at its lower end provided with an adjusting screw G, upon
which rests the male center H, which is rigidly secured to the traversing arm and
tapered to correspond to the female center. By the movement of screw G, the
friction between the parts F and H, may be varied and the free movement of the
traversing arm regulated. Two other points of support for the arm D, are
furnished by means of the rollers I, which are mounted on the platform of said
arm and roll upon the table C.
The
The traversing arm may be rotated about its center by any suitable means.
means illustrated consists of a friction roller J, mounted on the arm D, and bearing

page_text: upon the edge of the table C. This roller is by preference mounted as shown in
detail in Fig. 4, wherein a bracket J', is constructed for attachment to the under-
side of. the said arm, Figs. 1 and 3. In this bracket, by means of lateral
trunnions J³, is pivoted a frame J³, and in this the roller J, is journalled. This
manner of mounting the roller insures an even bearing thereof for its entire length
upon the edge of the table. The lower journal of the roller is extended through the
frame and upon it is fixed the bevel gear K. Meshing with this gear is the bevel
pinion K¹, and this is carried on the shaft K2, which is journalled in brackets
depending from the arm D. The outer end of the shaft K³, is provided with a
crank for rapid movement and with a milled head K³, for slight rotation of the
shaft in obtaining fine adjustment. It will be seen that by the rotation of the
shaft K2, the traversing arm may be rotated upon its center H. Obviously instead
of the friction roller and bevel gear, a spur gear might be cut on the edge of the
table and a pinion to mesh therewith substituted for the bevel pinion K¹.
The rotation of the traversing arm is for the purpose of obtaining the azimuth
of an object.
Various means may be adopted for indicating the azimuth. The one here shown
is of the quick-reading sort and is operated as the arm is rotated. This device has
a vertical shaft L, mounted in the platform of arm D, and provided with a friction
roller L, which engages with the edge of the table C. By this means rotation is
imparted to the shaft L. This shaft transmits motion to the scales or indicators of
the quick-reading azimuth device. For this purpose the shaft L, has a worm M;
cut thereon with. which meshes a worm wheel N, for the rotation of the degree
scale 0, which is located. in the casing O¹, and which displays its graduations
through an opening in the face of the casing, as seen in Fig. 3. Minutes of arc are
indicated by a disc P, located in the casing P₁, and rotated through a. train. of
multiplying gearing consisting of the gear Q, on shaft L, and, the pinion Q', in
mesh therewith and mounted on the same shaft as the scale P. The graduations.
of the scale P, are displayed through an opening in the face of casing. P¹, as seen
in Figs. 2 and 6. The pitch lines of the aforesaid gears, where seen in plan, are
represented by broken lines.
In order to place the traversing arm and these scales at an initial or zero position
the friction wheel L¹, is adjustably mounted upon the shaft L. This adjustment
may be made in any suitable manner; one way of accomplishing it, illustrated in
Fig. 2, consists in making wheel L', movable about shaft L, providing said shaft
with a conical nut L2; and a milled head, and in attaching a flexible disc L³, to
the face of wheel L', by screws which may clamp the conical nut between the wheel
and disc thereby fixing the wheel against rotation upon the shaft. To adjust the
azimuth scale to correspond with the zero position of the traversing arm. it is then
only necessary to loosen the screws in disc L³, give shaft L, the necessary rotation
by means of the milled head and then tighten said screws.
The rear end of the telescope is supported upon a vertically movable column R,
On the upper
guided in the bracket R', which is mounted upon the traversing arm.
end of this column is preferably mounted a grooved roller R³, upon which rests a
pin S, projecting from one of the cross-pieces of the telescope frame or support.
For raising the column a rack is formed upon it with which meshes a sector
gear T. This sector is journalled in a stand T, and is provided with an arm or
lever T, by which its movement is controlled.
Upon this platform of the traversing arm at the side of this stand is erected a
support U, in which is journalled a vertical screw U₁. Upon this screw is a nut
which carries a transverse slotted plate U³. Along the upper edge of this slot .is
located a scale and in the slot is a nut U³, threaded upon a screw U', which, in any
suitable manner, is fixed-against endwise movement in said plate. This screw is
provided with a milled head and as it is turned the nut U³, moves through the slot
to any desired position on the scale. Upon the face of the nut U³, is mounted a
small roller against which the arm T³, bears.

page_text: To rotate the screw U¹, and so raise or lower the plate U³, a bevel gear as at V,
may be employed, one pinion of which is upon the screw U¹, while the other is upon
a horizontal shaft carrying the crank V¹. For fine adjustments, may be used the
milled head V2, mounted with the crank upon this shaft.
The effect of the rotation of the screw U¹, and therefore the change in the eleva-
tion of the eye-piece of the telescope may be indicated by means of a disc as W,
which is journalled on a stud depending from the platform of the arm D, and is
provided with a toothed edge with which meshes the pinion W¹, mounted on the
lower end of the screw shaft U. The edge of this disc projects beyond the plat-
form of arm D, and is housed by casing W2, through an opening in which its
graduation may be read. This casing W2, is omitted in Fig. 3.
It is only necessary that such a portion of the weight of the telescope shall be
borne by the column R, and therefore by the arm T2, as will keep said arm in
intimate contact with the roller carried by nut U³, therefore the telescope is suit-
ably counterweighted as by weights located in the columns X, and joined to the
telescope supporting frame as by flexible connections X', which pass over suitable
pulleys on the top of said columns.
It will be seen then, by referring particularly to Fig. 3, that any rotation of the
screw U, will affect the elevation of the eye-piece of the telescope and the rotation
of the screw U', will also affect the elevation of the eye-piece of the telescope and
at the same time rotate the indicator disc W, from which may be read the range
of the object sighted, the ranges, within the capacity of the instrument, having
been computed for the various angles of depression, to which the telescope is
adapted, and marked upon the disc W. As the ranges vary unequally for
successive equal angles of depression, the scale is one of unequal graduation.
Each instrument is constructed to operate accurately at the elevations between
certain limits and for certain ranges. The adjustment of an instrument to a certain
altitude, or in other words to a certain vertical base, is effected by moving nut U
to the graduations upon its scale which corresponds to that particular base, said
scale having been plotted to correspond to the possible changes of base within the
capacity of the instrument. This scale on plate U³, may therefore be termed the
altitude scale.
Any movement of the nut U2, produces through the parts T2, T and R, a move-
ment in the telescope corresponding to the change of base indicated upon said scale.
A change of base through a change in location of the instrument must be corrected
for by moving this nut. Mean low-tide is taken as the initial point in reckoning
the working base, and any change in tide must be corrected for by moving this nut
the predetermined amount corresponding thereto.
In making observations the various ranges may if desired be plotted by means
of a suitable marker Y, movably mounted upon scales as Y', attached at one end to
the hub of arm D, and at the other to a bracket as Z, depending from said arm.
Paper being spread upon the table C, it only remains, when the range of an object
is determined, to move the marker to the point on the scale corresponding to the
range found and press it down onto the paper. Radial lines drawn from the center
of table C, will show the azimuths of the objects whose ranges are plotted.
For levelling the instrument, a suitable spirit level may be mounted as at &,
upon the arm D. Then by moving the arm first into the plane of one and then of
another leg of the pedestal A, and working the screws B, the instrument is speedily
brought to the proper position.
Before detailing the operation of the instrument it may be well to refer to the
diagram Fig. 8, and point out the difficulties in the way of a vertical base range
finder and how this invention overcomes such difficulties.
Let the heavy short line E, represent the telescope, c, its pivotal point, a, c,
the elevation of such point above mean low-tide, a, b, the apparent level of the
water, a, d, the true surface of the water, and c, e, a horizontal line through the
pivotal point of the telescope. Then were the telescope turned on an object at b,

page_text: the line of collimation would be e, b, and the right angle triangle c, a, b. The angle
of depression of the telescope would then be e, e, b, to which the angle c, b, a, is equal.
Then knowing the latter angle the horizontal distance or range of the object at b,
can be readily computed.
But an object in the water at the distance a, b, would on account of the curvature
of the earth, be at a point below b, as at d. To reach this object a greater
depression of the telescope is necessary but in effecting this depression the line of
collimation cuts the line a, b, as at r, and in computing the range of the object from
the new angle of depression e, c, d, and the base a, c, an erroneous range a, a, would
be obtained.
The distance of any point on the curve a, d, below the tangent a, b, is known
and an allowance on account thereof for each unit of range may be made on the
range scale W, in the construction of the machine, so that when an object is sighted
as at d, the true base for that range is the sum of the base a, c, and the dis-
tance (b, d,) which that object is below the tangent a, b, (or c, f,). The true
range f, d, is then readily obtainable.
In making this correction for curvature of the earth account must, be taken of
refraction of the atmosphere which has the effect of elevating the object above its
true position. This effect, under normal atmospheric conditions is found to be
about one-seventh the effect of curvature. This correction for mean refraction
being, on account of a permanent condition, for all ranges within the capacity of a
certain instrument, is in the construction of the instrument computed for each unit
of range indicated upon the scale W.
There are still two corrections which must be made for variable conditions such
as the rise and fall of tides and abnormal refraction. These corrections must be
made by adjustments in the instrument and will be brought out in describing the
operation of the instrument.
The instrument in the form just described, is set up and adjusted by means of
screw U, so that its working base equals its altitude above mean low-tide. Then,
when an observation is to be taken, the reading from a tide gage is obtained and
the nut U³, moved along to a point on the scale of plate U², cor-
responding to the working base for that particular height of tide.
This movement shifts the telescope into position for all ranges within the scope of
the instrument at that height of tide.
Then to correct for abnormal refraction the instrument may be set for the range
of some known object and if by turning it upon that object the horizontal cross-
hair of the telescope does not coincide with the water line thereof, the cross-hair
must be adjusted until such coincidence is effected. This is done by turning a
screw as E, which controls the position of such cross-hair, the cross-hair being
mounted in a vertically adjustable frame in the well known manner.
The instrument having been brought into consonance with the prevailing con-
ditions, the traversing arm is then moved in azimuth by the rotation of shaft K³,
until the telescope points in the direction of the object whose range is to be
determined. Then by turning the crank V, or head V2, the telescope will be
tilted until the horizontal cross-hair coincides with the water line of the object.
The range may be then immediately read directly from the scale W, in yards and
the azimuth read directly from the scales 0 and P, in degrees and minutes
respectively.
So rapidly can the parts of the instrument be manipulated that an object within
the field of the instrument may be accurately located in less than ten seconds and
if desired the course of a moving object may be plotted by points at intervals of
ten seconds.
It will be noted that the range and direction scales are operated by those
movements of the instrument by which an object is located and that as soon as the
object is located the readings may be directly taken from the scales without calcu-
lation of any sort. This is important as it enables any man of ordinary intelligence
to operate the instrument. It is also to be noted that the scales are operated through

page_text: trains of multiplying gear from parts of the instrument necessarily moved in
locating an object, and that in the azimuth indicating device the table of the instru-
ment is in reality the motor gearing of the train operating the degree and minute
scales. These constructions give instantaneous and accurate indications and
dispense with all forms of verniers.
The instrument as above described is adapted to be moved from one location to
another but is intended more especially for use at some fixed place, while the
instrument in the modified form illustrated in Figs. 9-12, is of lighter construc-
tion and especially designed for shifting from one location to another.
At such locations may be formed a base or foundation 13, of concrete or other
suitable material in which a pedestal 14, is secured. The pedestal may be provided
with any suitable means for attaching the stand of the instrument thereto, the one
shown consisting of a screw-threaded stud 15. The lower end of said stand may
consist of a plate or spider 16, near the outer periphery of which suitable depressions
may be made for the reception of leveling screws 17, which turn in arms 18, formed
upon the upper part of the stand 19. In the center of the part 19, is located a
cylindrical female center 20, which is secured in place by any suitable means as
the set screw 21. This center has formed upon its lower end an enlargement which
with the contracted upper end of the center portions of plate 16, constitutes a ball
and socket joint by which the upper portion of the stand is allowed freedom of
movement in all directions for the sake of adjustment. Through the female
center 20, is passed the male center 22, which has a flange at its upper end resting
upon the top of the center 20, and a nut upon its lower end turned against the
lower end of the center 20. In this way all the parts of the stand are held together
and yet allowance is made for the necessary adjustments. The upper end of the
center 22, is screw-threaded and passes through the table 23, into a suitable trans-
verse support such as the rib 24, which is provided with a hub at its middle for the
reception of said center and is secured in place diametrically across the table. This
rib projects upwardly at the forward end and has pivoted thereto at 25, the telescope
support 26, in which the telescope E2, is mounted in any suitable way, as by the
bands shown. A spirit level as &, is mounted upon the rib 24, and by turning
the table so as to bring said rib successively over the different adjusting screws of
the stand the instrument may be accurately levelled.
Upon the stand there is secured a circular rack or toothed plate 27, with which
meshes a pinion 28, which may be rotated by any suitable means as by a milled
head 281, located on the surface of the table 23. By means of this screw the table
may be moved for fine adjustment but the rotation thereof for any considerable
distance may be done by taking directly hold of the table.
By means of the parts just described the telescope may be moved in azimuth
upon any object. Various means may be adopted for determining the azimuth
of any object upon which the telescope is brought to bear. A quick-reading device
for this purpose is preferred, one form of which is illustrated in Figs. 10 and 12.
This device consists of the toothed plate 27, a pinion 36, which meshes with the
toothed plate 27, and is mounted upon a shaft located within the casing 29, mounted
upon the table 23; the gear 37, on the upper end of said shaft; the pinion 38, with
which gear 37, meshes; the pointer 39, mounted upon the shaft with pinion 38;
and the dial graduated to minutes of arc over which the pointer moves.
The degree
scale is marked upon the plate 27, and appears through an opening in the table
as at 40. This circular plate 27, serves as the motor gear of the quick reading
device. When the table has been moved to bring the telescope into a particular
direction the azimuth of the object sighted may be read immediately in degrees
and minutes from the indicator just described.
As above stated the pivotal point of support for the telescope is at 25. To raise
and lower the eye-piece of the telescope, a screw as 30, is mounted in the rear end
of the rib 24, and turned by means of the milled projection 30¹. Upon this screw
within an enlargement of the rear end of said rib is located a nut as 31, which is
capable of vertical movement in its support and is prevented from rotary movement

page_text: by a suitable feather indicated in dotted lines at 31. A slight groove is cut longi-
tudinally of the upper surface of this nut and in this groove rests the conical end
of an adjusting screw 32, which is also provided with a milled projection for turn-
ing it. This screw turns through a nut 32, mounted within a casing secured to
the rear end of the support 26. This casing is so constructed that a portion of the
nut projects through a slot in the side thereof and bears a line pointing to the
scale 32, marked upon the outside of said casing. Provision is also made for
movement of this nut longitudinally of the casing and such movement is produced
by means of the screw 33, which is secured against longitudinal movement in the
casing and provided with a milled head as shown. These three screws 30, 32
and 33, provide for the vertical movement of the eye-piece of the telescope for
special purposes hereinafter specified.
Any rotation of the screw 30, to move the telescope also actuates the range
scale 34, which consists of a circular toothed plate mounted to rotate upon the
stand 19, between the table and the plate 27. The graduations of this scale show
through an opening in the table 23, as at 35.
After this instrument is placed upon its pedestal and levelled up, the altitude
of the pivoted center of the telescope above low mean tide is obtained from any
suitable instrument, then the screw 33, is rotated to place the point of screw 32,
at such a position upon the nut 31, as will make the working base of the instrument
or the vertical of the right angle triangle for the observations from that station
equal to the altitude of the instrument. Then, when an observation is to be taken,
this working base is corrected for the condition of the tide by first obtaining the
heighth of tide from any suitable tide gauge, and then turning the screw 33, to
place the screw 32, in alignment with that degree of scale 32", which corresponds
to the vertical base with the tide at the height observed, the scale 32", having in
the construction of the machine been plotted for the adjustment of altitude and
correction for tide. This correction for tide shifts the telescope into position for
all ranges within the scope of the instrument at that height of tide. Then correc-
tion must be made for abnormal refraction. To do this the instrument may be set
for the range of some known object and if by turning it upon that object the
horizontal cross-hair of the telescope does not coincide with the water line thereof,
the eye-piece of the telescope must be raised or lower until such coincidence is
effected. This is done in this form of instrument by turning the screw 32. By
using the screw 32, for this purpose, the delicate micrometor adjustment employed
for shifting the cross-hair of the telescope in the other form of instrument may be
dispensed with.
The instrument having been corrected for tide and abnormal refraction, the table
is moved in azimuth, as above described, until the telescope points in the direction
of the object whose range is to be determined, then by turning the screw 30, the
telescope may be tilted until its horizontal cross-hair coincides with the water line
of the object. The range may be then immediately read directly from the
scale 34, in yards, and the azimuth read directly from the indicators 39 and 40,
in degrees and minutes.
It will be noted that in this form of the instrument also the direction or azimuth
indicator is operated by the movement of the instrument by which an object is
located, and that the range is also indicated by such movement so that as soon as
the object is located the readings may be directly taken from the scales without
correction or computation of any sort and without the use of verniers.
Many changes may be made in the form, construction and combination of the
parts of the instrument aside from those above described without departing from
the spirit of the invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. In a position finder, a telescope movable horizontally about a fixed point,

page_text: indices showing the angular movement of the telescope about said point in degrees
and minutes respectively, a train of multiplying gearing for operating the indices,
and means for rotating the telescope and at the same time actuating the train of
gearing so that upon fixing the telescope the correct azimuth thereof can be
immediately read upon the indices.
2. The combination with a support pivoted to rotate in a horizontal plane, a
telescope mounted thereon to tilt in a vertical plane, gear mechanism for rotating
the support, an azimuth reading device operated by the movement of the support
and constructed to give in degrees and minutes immediate indications of the
azimuths of the telescope, means for tilting the telescope to observe an object, and
a quick reading device carried by the support and operated to give the range of the
object by tilting the telescope to sight the object.
3. In a range finder, the combination with the telescope, of mechanism for tilt-
ing it in a vertical plane, a device operating upon said mechanism for fixing and
correcting the working base of the instrument, and an indicator operated by the
tilting mechanism and graduated to show at a glance the exact range of any object
observed.
4. The combination with a telescope mounted for depression, of a range scale
graduated in units of distance, an operating shaft, gear mechanism between the
same and the telescope, and gear mechanism between said shaft and the range
scale whereby through rotation of said shaft the telescope and the scale may be
moved together, as and for the purpose set forth.
5. In a range and position finder, a range scale the units of which are corrected
for normal refraction, and adjustment means for making corrections for abnormal
refraction.
6. The combination with a telescope mounted to move horizontally about a center,
of a quick-reading azimuth device having two sets of pointers and scales graduated
to degrees and minutes respectively and all mounted to move with the telescope,
and means whereby the horizontal movement of the telescope communicates motion
to the movable parts of the azimuth device.
7. The combination with a telescope mounted on a table to move horizontally
about a center, of a quick-reading azimuth device mounted with the telescope and
of which the indices are connected by a train of gearing to the table so that as the
telescope is moved about said center the azimuth device will be actuated and will
give in degrees and minutes an immediate indication of any position of the
telescope.
8. The combination with the table, of the traversing arm pivotally mounted
thereon, the telescope swung on said arm, gearing connecting the arm to the table,
means for rotating the gearing, and an azimuth reading device mounted on said
arm and also having an operating connection with the table whereby as the arm
is moved its every position will be indicated in degrees and minutes.
9. The combination with the table, of the traversing arm pivotally mounted at
the center of the table, a bracket J₁, secured to the underside of said arm, a frame
horizontally pivoted in said bracket, a friction roller journalled vertically in said
frame, and means for turning said roller to make said arm traverse the table.
10. The combination of the telescope pivoted to move in a vertical plane, a verti-
cally movable support for the eye-piece thereof, a lever for moving said support, a
range scale as W, a vertical screw, a plate movable thereon and carrying a pro-
jection engaging one end of said lever, and a pinion carried by said screw for rotat-
ing said scale.
11. The combination of the traversing arm, the telescope support pivoted thereon,
the telescope, the vertically movable column under the eye-piece end of the tele-
scope, the counter-weights, and means for gradually raising and lowering said
column.
12. The combination with the tilting telescope, the column under the eye-piece
end thereof, the lever for moving said column, the vertical rotary screw,
the plate
moved vertically thereby, a rotary screw horizontally mounted in said plate, a nut

page_text: movable thereby and having a projection engaging with said lever, a scale on said
plate by which to locate said nut, and an index operated by the vertical screw to
give the range of an object observed.
13. In a range finder, the combination with a telescope pivoted for depression,
of a range scale having unequal graduations, a lever for moving the telescope about
its pivot, and a device for imparting movement to the range scale and having a
projection movable in a right line and engaging with said lever for imparting
movement to the telescope.
14. In a range finder, the combination with a telescope mounted to tilt in a
vertical plane, of a vertically movable support for the eye-piece of the telescope,
an indicator for indicating the range, a lever pivoted on a fixed support, and a stud
or projection moving in a right line and engaging the lever, said lever and pro-
jection being interposed between the telescope and indicator, as and for the purpose
described.
15. In a range finder, the combination with a vertically tilting telescope, a lever
for moving said telescope to desired angles of depression, a projection engaging
said lever and adjustable towards or from the fulcrum of the lever to correct for
variations in the base of triangulation, and means for moving said projection
vertically and thereby tilting the lever and the telescope.
16. The combination of the telescope pivoted to move in a vertical plane, a verti-
cally movable column as R, supporting the eye-piece end thereof and having a
movable connection therewith, a rack upon one side of said column, a sector lever
engaging with said rack, a range indicator, and means for actuating said lever and
indicator simultaneously.
17. The combination with the table and the traversing arm centrally pivoted
upon the table, an azimuth indicating device mounted upon said arm and having
an operating shaft carried by the arm for transmitting motion to the indices, a
wheel on the shaft, and means for adjusting said shaft within said wheel.
18. The combination with the table and the motor shaft of the azimuth indicator,
of the wheel upon said shaft, the cone upon the shaft, the plate bearing upon the
cone and the wheel, and means for clamping the cone between the wheel and plate
to secure the former rigidly to the shaft.
19. In a range finder, an adjustment device for abnormal refraction located
between the telescope and the range adjustment mechanism, and an indicator
operated by the range adjustment mechanism.
20. In a depression range finder, the combination with a telescope mounted to
tilt in a vertical plane, mechanism for tilting the telescope to obtain the range of
an object, and means interposed between said mechanism and the telescope to make
correction for abnormal refraction, and an indicator operated by said tilting
mechanism.
21. The combination with a telescope mounted to tilt in a vertical plane,
mechanism for vertically adjusting the eye-piece thereof, means interposed between
said mechanism and the telescone for changing the base of triangulation, and a
device acting independently of said means and mechanism to tilt the telescope and
thereby make correction for abnormal refraction.
22. In a range and position finder, the combination with a telescope pivotally
mounted for movement in a vertical plane, of a support under the telescope, and
means for adjusting said support longitudinally of the telescope to effect a definite
change in the base of triangulation.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.