Improvements in Surveying Levels.
Year: 1893

page_text: Date of Application, 22nd Sept., 1893-Accepted, 28th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in Surveying Levels.
A communication from THOMAS BOLTON, Surveyor, India Departinent, 17, Camac
Street, Calcutta, India.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
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 levels for engineering and surveying purposes, the
telescope being so arranged that it can be easily taken out of its bearings and
reversed for adjustment purposes without disturbing the rest of the instrument.
The invention will be best understood by reference to the accompanying drawing
which is a side elevation.
A represents the telescope provided with object-glass, eye-piece, draw tube with
rack motion, and screws Q for adjusting the cross wires usually employed in
telescopes of this description. The telescope A is carried in standards
or Ys B having semi-circular jaws in which the telescope lies so that it can
be revolved without disturbing the rest of the instrument: it may either simply
rest in the jaws of the standard or it may be secured therein by any suitable form
of cap. The standards B may be provided with spring or other caps or the like
adapted to prevent the telescope from escaping from the jaws and suitable friction
devices may be employed to prevent it from turning too easily; the telescope can
be fixed absolutely in the standards B by the screws C which pass through the
flanges A of the telescope and screw into the standards B.
The standards B are made sufficiently high to allow room for the spirit level D
between the under side of the telescope A and the compass box E which may be
carried in the bed plate F in the ordinary manner. By so placing and fitting the
spirit level D that it is independent of the telescope A the adjustments can be more
easily and better made and the telescope can be lifted out of its supports and
reversed without disturbing the spirit level or interfering with the adjustments,
also the optical arrangements of the telescope need not be disturbed in turning it
end for end.
The spirit level D is carried at one end by a plate spring G fastened by screws (+
to the standard B and at the other end by a tongue H passing through a slot B₁ in
the other standard B. Through the tongue H passes a screw 1 fixed by a
pin I' in the standard B and bearing nuts J by turning which the tongue H and
consequently that end of the level can be raised or lowered as required. The
nuts may be turned by having milled edges which project beyond the standard,
or they may be provided with holes J' and thus turned by a capstan pin.
One of the standards B is jointed to or suitably carried by the base plate F and
the other one is adjustable in the base plate by the screw K fixed in the standard
and passing through a central web F¹ in the base plate; upon the screw K are two
nuts L by turning which the screw K and with it the standard B and the end of the
telescope supported therein can be raised or lowered as desired. These nuts L can
be turned in the manner described with reference to the nuts J; the screw K may
with advantage be part of the same piece of metal as the screw I so that the one
pin I will fasten both screws in the standard.
The legs and top of the stand may be of usual construction, bolts M with milled
heads M being conveniently employed for roughly adjusting the level or for bodily
raising or lowering the telescope and fittings.
N is a small cross level also placed beneath the telescope at right angles to the
long level D for roughly levelling the instrument.

page_text: Having now particularly described and ascertained the nature of the said
invention, as communicated to me by my foreign correspondent, and in what
manner the same is to be performed, I declare that what I claim is :-
1. In a surveying level a telescope lying in supports or standards such as B and
having no spirit level attachments.
2. In an instrument such as described placing the level D below the telescope A
and independent thereof substantially as described and illustrated in the accom-
panying drawing.
3. In an instrument such as described the combination with a telescope A
carried in forked standards such as B of a spirit level such as D fixed to one
standard so that its height cannot vary, and vertically adjustable in the other
standard substantially as described and illustrated in the accompanying drawing.
4. In an instrument such as described the combination with a spirit level such as D
of a plate spring such as G at one end secured to one of the standards or telescope
supports B and an adjustable screw device such as H I J at the other end and
carried in the other standard substantially as described and illustrated in the
accompanying drawing.
5. In an instrument such as described the combination with a jawed standard
such as B of a screw such as I K for the purpose of adjusting the standard upon
the base plate F and also the spirit level D within the standard substantially as
described and illustrated in the accompanying drawing.
6. The combination and arrangement of parts constituting the complete surveying
level substantially as described and illustrated in the accompanying drawing.
Dated this 20th day of September 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.