AN IMPROVED INSTRUMENT FOR LEVELLING AND FOR MEASURING ANGLES
Year: 1869

page_text: LETTERS PATENT to William Lloyd Wise, of Chandos Chambers,
Adelphi, in the City of Westminster, Consulting Engineer and
Patent Agent, for the Invention of "AN IMPROVED INSTRUMENT FOR
LEVELLING AND FOR MEASURING ANGLES." -A communication from
■1 1…. Kukotelon's Souss and Company of Paris, France.
Sealed the 10th June 1870, and dated the 18th December 1869.
PROVISIONAL SPECIFICATION left by the said William Lloyd Wise
at the Office of the Commissioners of Patents, with his Petition,
on the 18th December 1869.
I, WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the City
of Westminster, Consulting Engineer and Patent Agent, do hereby
declare the nature of the said Invention for "AN IMPROVED INSTRUMENT FOR
LEVELLING AND FOR MEASURING ANGLES," to be as follows:-
The object of this Invention is to obtain in a more prompt and exact
manner than has been heretofore accomplished geometrical or other
levels, also the measurement of angles either horizontally or vertically,
and consists in a novel arrangement of instrument composed of three

page_text: principal parts, namely, first, a three-legged strand or tripod, the legs of
which are united at their upper ends by suitable hinges or joints to a
hollow hemisphere in which the instrument proper rests, the said
hemisphere containing a cross piece which carries knife edges resembling
those of a scale beam, so arranged that the instrument proper rests upon
them in such a manner as to be free to adjust itself by the action of its
own gravity. Second, a pendulum screwed into the centre of the said
instrument, which passes freely through an opening in the centre of the
lower part of the hollow hemisphere which forms the top of the tripod
herein-before referred to. This pendulum is furnished at its lower
extremity with a hook, to which a plumb line may be attached to
indicate the position in which a stake should be placed. The pendulum
when screwed on by its gravity causes the instrument to instantly
assume a truly horizontal position, in which it is afterwards secured by a
set screw fixed in the hemisphere. Third, an apparatus provided with
a worm wheel and worm and annular index, the number of teeth in the
worm wheel and pitch of the worm being such that each revolution of
the worm shall indicate one degree on the annular index, the worm
being further provided with a head, which serves as a micrometer wheel
for indicating the fractions of a degree, which may be arranged either in
hundredths or in minutes and seconds. Vertical measurements and
those of distance are obtained by means of a tangent screw, the pitch of
which is so adjusted as to indicate or measure the proper divisions.
Several gauges are fixed to the upper plate of the instrument (eight
being the number chosen), and serve for taking the lines of sight, there
being mirrors arranged in the centre of the instrument in such a manner
that the line of sight may be taken either forward or backward, the
mirrors being placed at known angles and acting as reflectors. The
instrument may be taken to pieces, and its various parts used separately
to suit special requirements, such as for the use of artillery, for scientific
purposes, railway and geometrical surveys, and so forth. The leading
peculiarities may be stated briefly as, first, the application of the
pendulum for rapidly obtaining true levels; second, the application of
the gauges above the mirrors for the purpose of expediting operations;
and, third, the application of the mirrors so as to allow of work being
done from behind without displacement.

page_text: 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 18th June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
LLOYD WISE, of Chandos Chambers, Adelphi, in the City of Westminster,
Consulting Engineer and Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of December, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Lloyd Wise, Her
special licence that I, the said William Lloyd Wise, my executors,
administrators, and assigns, or such others as I, the said William
Lloyd Wise, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, usc, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "AN IMPROVED INSTRUMENT FOR LEVELLING AND FOR MEASURING
ANGLES," a communication to me from abroad by Kukatzkay's, Seyss, and
Company, of Paris, France, upon the condition (amongst others) that I,
the said William Lloyd Wise, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Lloyd Wise, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
The object of this Invention is to obtain in a more prompt and exact
manner than has been heretofore accomplished geometrical or other
levels, also the measurement of angles either horizontally or vertically,
and it consists in a novel arrangement of instrument composed of three
principal parts, namely, first, a three-legged stand or tripod, the legs of

page_text: which are united at their upper ends by suitable hinges or joints to a
hollow hemisphere in which the instrument proper rests, the said
hemisphere containing a cross piece which carries knife edges resembling
those of a scale beam, so arranged that the instrument proper rests upon
them in such a manner as to be free to adjust itself by the action of its
own gravity. Second, a pendulum screwed into the centre of the said
instrument, which passes freely through an opening in the centre of the
lower part of the hollow hemisphere which forms the top of the tripod
herein-before referred to. This pendulum is furnished at its lower
extremity with a hook, to which a plumb line may be attached to
indicate the position in which a stake should be placed. The pendulum
when screwed on by its gravity causes the instrument to instantly
assume a truly horizontal position, in which it is afterwards secured by a
set screw fixed in the hemisphere. Third, an apparatus provided with
a worm wheel and worm and annular index, the number of teeth in the
worm wheel and pitch of the worm being such that each revolution of
the worm shall indicate one degree on the annular index, the worm
being further provided with a head, which serves as a micrometer wheel
for indicating the fractions of a degree, which may be arranged either in
hundredths or in minutes and seconds. Vertical measurements and those
of distance are obtained by means of a tangent screw, the pitch of which
is so adjusted as to indicate or measure the proper divisions. Several
gauges are fixed to the upper plate of the instrument (eight being the
number chosen), and serve for taking the lines of sight, there being
mirrors arranged in the centre of the instrument in such a manner that
the line of sight may be taken either forward or backward, the mirrors
being placed at known angles and acting as reflectors. The instrument
may be taken to pieces and its various parts used separately to suit
special requirements, such as for the use of artillery, for scientific
purposes, railway and geometrical surveys, and so forth. The leading
peculiarities may be stated briefly as, first, the application of the
pendulum for rapidly obtaining true levels; second, the application of
the gauges above the mirrors for the purpose of expediting operations;
and, third, the application of the mirrors so as to allow of work being
done from behind without displacement.
Fig. 1 represents a vertical section of the instrument with a portion of
its tripod, and shews its pendulum M screwed into the centre of the
spherical part of the instrument after passing through the opening in the

page_text: centre of the intermediate piece shewn in Fig. 6. Figs. 2 and 3 plans
of parts of the instrument. Figs. 4, 5, and 10, elevation, plan, and end
view of the cross piece shewing the prismatic recesses for receiving the
knife edges of the intermediate piece. Figs. 6 and 11, plan and elevation
of the intermediate piece, which is formed with prismatic recesses to
receive the knife edges of the instrument. This intermediate piece is
also formed with two prismatic projections or knife edges, which rest in
the prismatic recesses of the cross piece shewn in Figs. 4, 5, and 10.
Fig. 7, a section shewing the upper part of the instrument at right
angles to Fig. 1. Fig. 8, a plan shewing the mirrors and gauges affixed
to the under side of the upper plate. Figs. 9 and 12, elevation and plan
of the knife edges of the instrument.
The following is a description of the instrument and of the manner of
using it, as communicated to me by my foreign correspondents:-
A (Fig. 1), set screw fixed in the upper circle of the tripod, and
serving to prevent the base of the instrument moving as soon as it has
assumed its horizontal position or level. D (Figs. 1, 2, and 7), dis-
engaging screw, when it is screwed up it allows the instrument to turn
completely upon the circle on which the degrees are marked at the
bevilled part in front, when it is unscrewed the apparatus is fixed and
becomes rigid. B (Figs. 1, 2, and 7), thread of worm cut in such
manner that its turns represent the value of entire degrees which may be
read upon the periphery of the circle, whilst at the divided head of the
worm may be read the hundredths (or it may if desired be divided into
minutes and seconds). It is thrown out of gear by the tightening of the
screw D above described. The vertical measurement and the measure-
ment of distance are taken by means of the tangential screw C (Figs. 1
and 2), whose pitch is exactly th of the radius. It thus represents
the greatest cathetus known of a right angled triangle, of which the
smallest may be measured by the screw in adjusting itself to the gauge.
A perfect indication is thereby obtained on the instrument of a small
known triangle, the greatest having to be ascertained, and as in adjusting
the first we commence by the horizontal lines, the gauge gives exactly
the horizontal distances, that is to say, whilst measuring the heights it
gives the distance required of the horizontals.
a, b, c, d, e, f, g, h, Fig. 8, represent in plan 8 gauges of which the
form and exact design are represented in section at a, g, in Fig. 1; they
serve to take the lines of sight either in front by making use of the

page_text: line b, g, which passes above the mirrors, and which cuts the axis at
right angles if we measure with the tangential line, or behind by making
use of the mirrors and of the line c, 8, b, or f, 8, 9. V, mirror of which
the form, angle, and the heights are indicated in section and in plan in
Figs. 1 and 8. p and q, Fig. 1, screws, which serve by tightening them
more or less to regulate the course or movement of the screws which
serve to divide the fractions of a degree, so that the division may be
perfect.
=
N
Let D: d=N: n or D: N=d: n, Fig. 1, or D represents the distance
of the staff from the instrument; d, the constant of the instrument
(here=60); N, the known distance to be chosen in simple measurements
of two marks or points upon a staff; and n the reading upon the screw;
in deducting the lower position from the upper if the first did not
equal 0, that is to say, in the horizontal, and D=N: n, or H, the
distance of the lower disc of the horizontals, and the reading upon the
screw of the horizontal (=0=) as far as the gauge marked upon the
lower disc, thus, H; is then the measure in which N is measured.
It is possible to measure heights and distances at the same time and in
different directions from one point, it is necessary to consider the height
of the instrument (the lines of sight measured in horizontal position)
and the distance of the lower disc from the foot of the staff. The right
angles may be gauged directly with a sd, and e8 h, Fig. 8; the angle
of 60 degrees is indicated by the gauges ah and cf, that of 30 degrees
by the gauges ah, and bg; that of 15 degrees by the gauges ag, and
bg, pointing to the upper lines of sight. In the mirror the angles
of 30 degrees are indicated by the gauges bs c, and gfs; these
indications are seen at once by observing that the mirror cuts the
vertical axis at 15°, and that the lines of sight are distant from them
30 deg.
Having now described the nature of the said Invention of an improved
instrument for levelling and measuring angles (to which my foreign
correspondents have given the name of "Lontanid "), I would remark
that the operations of the instrument may be extended or diminished by

page_text: the use of telescopes, or by reducing the measurements of heights as
may be necessary, so as to serve for artillery, for staff officers, or for
geometrical surveying; but that what I claim as new and desire to have
secured to me by the herein-before in part recited Letters Patent is,―
Firstly. The application of the pendulum M for rapidly obtaining true
levels.
Secondly. The application of the gauges visible above the mirrors and
reflected in them at the base at regular intervals under known angles,
for the purpose of expediting operations and ensuring greater exactness.
Thirdly. The application of the mirrors so as to allow of work being
done from behind without displacement.
In witness whereof, I, the said William Lloyd Wise, have hereunto
set my hand and seal, this Sixteenth day of June, in the year of
our Lord One thousand eight hundred and seventy.
W. LLOYD WISE. (L.S.)