IMPROVEMENTS IN TELEMETERS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the Com-
missioners of Patents on the 25th June 1877. A communication from
Ernst von Paschwitz, Engineer, residing at Peissenberg, near Munich, and
Carl von Paschwitz, Engineer, residing at Kissingen, both in the Empire of
Germany.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Agency, of Frank-
fort-on-the-Maine, in the Empire of Germany. "IMPROVEMENTS IN TELEMETERS."
[A communication from Ernst von Paschwitz, Engineer, residing at Peissenberg,
near Munich, and Carl von Paschwitz, Engineer, residing at Kissingen, both in the
Empire of Germany.]
A telemeter according to this Invention consists of the following parts :-
1st. The optical instrument.
2nd. The two supports.
3rd. The measuring rod.
4th. The compensation.
5th. The aiming table.
First. The optical instrument is a telescope with crossed thread and an angle
mirror. The mirror is placed before the telescope, and covers half the object lens,
and diverging the rays of light to an angle under 90 degrees, say 89 degrees, in
order that the measuring rod described under the third head may be held in balance.
On the outside of the telescope are two rings, by means of which the telescope is
supported in the jaws of two uprights or supports, and is free to move round its
axis.
In the mirror case there is arranged a "diopter," the aiming line of which covers
that of the angle mirror. The latter consists of a plain convex glass lens, on the
convex side of which is ground a plane surface of one / diameter. There is also
an aiming pin arranged in the focus of the lens.
Near the object lens there is arranged a semicircular compensating lens, by
means of which the optical figures of the removed object and that of the nearer
aiming table are united in the plane of the crossed thread.
The two supports are arranged with jaws or beds, into which the instrument is
laid.

page_text: The said jaws or beds are provided with any suitable mechanical arrangement for
moving the instrument horizontally and vertically.
The supports when in use may be placed at a distance 25 metres one from
another.
The measuring rod is about one metre long, and is, when used, fixed by means of
the brass rail (described under the fourth head) on the bed or jaw of the support.
The said rod is provided with two scales of distance, one fine scale arranged on the
upper side and one course scale arranged on the lateral side.
The divisions of the scale may embrace distances from 600 to 1,000 metres.
The compensating implement consists of an aiming rod and a brass rail, both
having scales of equal divisions.
The aiming rod is fixed on the bed or jaw of the support, and is provided with
a "diopter" having the same aiming line as the telescope, and also has in like
manner to the measuring rod a finer scale on the upper side, and a coarser one on
the lateral side.
The brass rail is fixed on the measuring rod, so that it projects equal distances on
both sides.
The aiming table is made to slide on the measuring and aiming rods, and is
provided with a vertical line for directing the same with respect to the crossed
thread, and with a hand or pointer for reading the number.