Improvements in Lantern Microscopes, Forming an Instrument that can be used on the Magic Lantern or as a Table Microscope.
Year: 1890

page_text: Date of Application, 11th Nov., 1890
Complete Specification Left, 19th June, 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Lantern Microscopes, Forming an Instrument that
can be used on the Magic Lantern or as a Table Microscope.
ROBERT GEORGE MASON Optician of 24 Clapham Park Road, Clapham in the
County of Surrey do hereby declare the nature of this invention to be as follows:-
It consists of an ordinary flat brass stage as in use in students microscopes, with
a diaphragm let into it, this may be either above or below and comes level with the
face of same, attached to this stage is a form of arm or limb often used on table
microscopes, with a rack and pinion for focussing and a screw fine motion for same.
Up to the present the lantern microscope and the table microscope have been two
distinct instruments. By my invention, the one instrument is able to be used for
table purposes, or on the magic lantern for projecting the object on to a screen, so
that it may be seen by a number of persons at once. It is done by making the stage
with duplicate plates, dovetailed with a spring dovetail at one side, so that either
part may be used.
ROBERT GEORGE MASON.
COMPLETE SPECIFICATION.
Improvements in Lantern Microscopes, Forming an Instrument that
can be used on the Magic Lantern or as a Table Microscope.
ROBERT GEORGE MASON of 69 (formerly of No. 24) Clapham Park Road
Clapham in the County of Surrey Optician 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 :---
of
The object of my invention is to enable the magic-lantern or projection microscope,
as it is often called to be used for two purposes, that is for demonstrating to a number
persons at once, or by the use of my improvements to alter the same instrument
into a microscope such as is used on the table, in the ordinary way or vice versa;
this to my belief has never been done before, the two instruments having been until
now separate and distinct instruments for each purpose. My method of doing this
I now proceed to describe. I use existing forms of microscope stages known as
the "plain" and "mechanical." At the underneath side of the lower plate 1 fix,
by means of screws or other methods as occasion may require, two dovetail pieces
of brass or other durable metal so forming guides as holding means. I arrange two
dovetail plates to fit firmly into the aforesaid dovetailed pieces on the stage plate,
one of these dovetail plates has fixed to it the tubes containing the optical system
of lenses for use with the magic lantern or projection form of instrument; the other
plate has fixed to it the one half of an ordinary joint such as is used to incline the
upper portion of microscopes at any angle. These plates are stopped from sliding
right through by a small stop on the main plate or by means of screws screwed into
the main plate where required, so that the removable parts, that is, the two plates
one attached to the tubes containing the optical system of lenses as before mentioned,
and the other fixed to the joint of the table stand, are exactly central to the optical
axis of the instrument when pushed into or secured in their respective position
under the main stage plate. The plate carrying the optical system of lenses is
provided with a screw at or near the end of the outer tube for screwing into the
front of a magic lantern.
Secondly. On the upper surface of the main stage plate is fixed the arm or limb

page_text: that carries the coarse adjustment provided with a rack and pinion, also the usual
fine screw adjustment. On the slide of the coarse adjustment is fixed a tube, this
tube is made to carry either the brass tube or body for the table stand form, or a
small short tube carrying the "objective" in the lantern or projection form of
instrument, the main stage being removable from the smaller plates enables the
subcondensor lenses to be easily changed if circumstances require.
In the drawings annexed hereto is illustrated the application of the said invention
for a magic lantern and also for a table microscope.
Fig. 1. Sheet 1. shows the arrangement of the instrument as used for the magic
lantern or projection purposes.
Fig. 2 shows the arrangement of the instrument as for the table form of
microscope, with the table stand of substantially ordinary form.
Fig. 3 shows the main stage plate with the plate of the table stand for microscope
in dotted lines.
Fig. 4 shows the dovetail plate for the microscope table stand with ordinary
knuckle joint thereof and
Fig. 5 is a section of the said two plates in position.
Fig. 6 is the dovetail plate for the lantern construction which is a fixture to the
tubes of the optical system of lenses for use with the magic lantern (see Fig. 1).
Fig. 7 is a section showing these two plates in position.
Fig. 8 is a like view to Fig. 3 but with the lantern optical system plate in dotted
lines.
Referring to Figs. 1, 6, 7, and 8, A, are the tubes ordinarily employed for carrying
the optical system of lenses for use with the magic lantern; B, is the attachment
plate with dovetailed edge fitting the dovetail slide pieces B' fixed on the main-
stage plate C. D is a spring holder tube, affixed to the upper part of a dovetail
slide fitted with a rack adjustment E for focusing, said holder tube to carry the
carrier D' for the "objective" in the lantern form; or, the microscope body D², in
that arrangement of the instrument. The limb F, of the stage portion carries the
coarse and fine focusing adjustments E, E¹, for the carrier D. The screw A¹, Fig. 1,
is for the purpose of screwing into the front plate of a magic lantern body (not
shown).
For stopping the slide plates B in position, screws or stop studs C¹, are provided
upon the main stage plate C.
In the arrangement shown in Figs. 2, 3, 4, and 5 the table stand A², and
inclination joint A³, are old but carry the slide plate B, which will slide into
the guides B', of the main stage plate, C, like letters referring to similar parts in
all the figures.
The plates B, B, may have other means provided for holding same together in
the different positions such as pins and slots or corresponding holes and screws or
by sliding tube and socket.
The main stage plate is secured to the instrument by the tail piece C².
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is
1. The combination of the parts of a microscope so as to form an instrument that
can be used both on the magic lantern for projecting purposes, or as a table
microscope substantially as and for the purpose herein set forth.
Dated this Sixteenth day of June 1891.
ROBERT GEORGE MASON.