An Improved Compass Attachment for Marine or Field Glasses, for Taking Observations at Sea or on Land, and for other like purposes.
Year: 1891

page_text: Date of Application, 13th Jan., 1891-Accepted, 14th Feb., 1891
[Communicated from abroad by EDWARD GEORGE KING, of 5, Market Place,
San Francisco, California, United States of America.]
An Improved Compass Attachment for Marine or Field Glasses, for
Taking Observations at Sea or on Land, and for other like
purposes.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 :-
The nature of this invention is to provide a means for taking observations at sea
or on land either in the night time or day time by use of a single instrument, and
my invention consists in the arrangement and combination of parts hereinafter set
forth and pointed out in the claims.
In the drawings which form part of this Specification:-
Figure 1 is a plan or top view of my compass attachment to marine and field glasses."
Figure 2 is a transverse section of the same taken just in front of the compass.
In carrying out my invention I preferably employ a Ritchie or fluid compass A
the box or case of which is permanently fixed to the glass B between the tubes or
barrels thereof by means of a saddle C, a little distance back or to the rear of the
object glasses or lenses, the lower end of the saddle frame being permanently
connected centrally between the tubes as shown in Figure 2 yet so as to be clear
of the tubes. The adjustment of the compass of the glasses is such as to be on
exact line with the axis of the object glasses so that correct bearings can be
taken.
The box or compass containing case is connected to the arms of gimbals D D of
the saddle frame and the dial plate E of the compass swings freely in the case in
the usual manner and has free movement in the case or box during the time of
taking the observation. When this is accomplished however, a set or stop-screw
attachment F is made to operate against or upon the dial plate and hold it immovable
in the required position until the calculation has been made; it is then released again
for taking other and further observation.
This set-screw or stop is arranged at one side of the box or compass containing
the case and holds the dial plate or compass firmly in position immediately as the
stop-screw is acted upon after the observation has been taken.
As thus constructed, arranged and combined, it will be seen that the compass
attachment with the glass is always in position and can be taken aloft as well as on
deck in the night time as well as in the day time for furnishing magnetic bearings
without the aid of separate instruments or a
< dumb compass
at the mast head or
taff-rail for taking relative bearings.
"
In order to take a bearing from the standing compass, the glass must be removed
from the eye before the bearing can be taken in which case the object may be from
one and a half to two points off.
.
With the instruments now in use for taking bearings such as the Pelorus, Aledade
or Azimuth compass, which are not portable, the object must be in view with the
naked eye from the deck of the vessel, when it frequently happens that the sails or
other objects are in the way and the bearings cannot be taken until the obstruction
has disappeared. With applicant's instrument a bearing of any object from any
part of the vessel can be had and the bearing taken instantaneously.
It is sometimes important to obtain the bearing of a light as soon as seen from
the mast head. With applicant's instrument this is an easy matter, as the instrument
can be taken to any part of the vessel and instantly made available.

page_text: Cross-bearings or positions of polar stars can also be readily taken by this
instrument. Running lines or boat surveying can be made with the instrument
which cannot be made with any telescope or surveying instrument now in use.
It will be seen that my glass and compass attachment will be useful and valuable
for taking observation on land or in the heavens as well as on the sea, either in the
night time or in the day time.
Furthermore my invention will be of great utility in boat or marine surveying.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1.In a field or marine glass the saddle frame permanently connected to the
glass between the tubes or barrels thereof, to the arms or gimbals of which is
connected a compass containing case provided with a set-screw or stop engaging
with the dial plate or compass, substantially as and for the purpose herein set forth
and specified.
2. The combination and arrangement with a field or marine glass of a compass
containing case for taking observation at sea or on land, arranged and operating in
the manner substantially as described.
Dated this 14th day of November 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.