Year: 1888

page_text: Date of Application, 24th Mar., 1888
Specification Accepted, 1st June, 1888
WILLIAM CHARLES HUGHES Brewster House 82 Mortimer Road Kingsland N.
London 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 :-
This invention relates to a revolving lantern body Figs. 1 & 2 for either Electric or
Oxy-hydrogen light of Hexagon or octogon form, rotating on ball or wheel rollers
M M M Fig. 2 working on brass base B to be used with the Lantern Microscope P and
other projecting apparatus employed by scientific & other lecturers for throwing
experiments, objects or views upon the screen. This apparatus is provided with an
arrangement of centering by means of spring & click bringing all the Instruments in
use perfectly true on the screen. Hitherto this has only been effected by using separate
instruments, but by using this arrangement, a series of experiments, can be shown
with rapidity and certainty.
The loss of light hitherto has been a serious defect in these forms of instruments
owing to the marginal rays that are taken up from the radiant (the lamp or other
source of light) by the first condensing lens being lost.
To obviate this I have constructed a special form of Triple condensers E E using a
plano-convex lens first second a double convex lens and the third lens a meniscus,
the curvatures of these is so arranged that edge rays are entirely used, and a perfect
cone of light of the maximum power obtained. These I have applied to the lantern
microscope, and am able to obtain as a result brilliant illumination and perfect
definition on the screen. The light passing from these condensers is deprived of its
heat rays by means of an alum Trough F, which may be of any ordinary construction,
having glass sides.
This enables the most delicate objects to remain in the lantern for a long period,
without the slightest fear of injury. In order to utilize the whole of the light
obtained from the primary condensers and to throw it upon the object the rack
substage is fitted with a standard size tube and any good form of substage illuminators
can be used according to the requirements of the objectives in use.
The objectives of any ordinary table microscope may be used, but I employ a series
of forms of lenses, the curvature of which have been worked out to produce a

page_text: specially flat field and pass the largest amount of light, thus giving brilliant
illuminations and definition. Instead of the object lying upon a fixed stage as in the
ordinary microscope lantern, 1 employ a mechanical stage Fig. 3. H with double screw
action, giving rectangular motions so that any portion of the object can be easily and
rapidly brought under observation, the revolving wheel of diaphragms I to be used as
stops is brought up immediately behind the object, but at such a distance that the
object freely passes over it. The same being held in position by means of Spring
clips with sufficient adjustment to allow of the Zoophyte trough being as easily held
as the ordinary microscopic slide.
The apparatus having base boards B O Figs. 1 & 2 when in use, are made to detach
from the front of lantern by means of a bayonet catch so that they are easily
removable and admit of the whole apparatus being packed in a very small space. In
the accompanying drawings, I have shown a base plan Fig. 1. with apparatus attached.
Fig. 2, elevation of same showing Lantern microscope in position removed.
Fig. 3, is front view of mechanical stage, showing wheel of diaphragms. A is the
body of lantern which revolves on brass circle B by means of ball or wheel rollers.
C is the Gilchrist form of projecting lantern. P Lantern microscope with special
condensers E E. F is the alum trough of ordinary construction G is the substage
condenser fittings of standard size to admit of the use of ordinary substage illuminating
apparatus H Mechanical stage I Rotating wheel of diaphragms J. Object glass
carrier fitted with fine adjustment.
The instrument is fitted with coarse rack adjustment placed in such a position that
vibratory motions are reduced to a minimum K optical Lantern for diagrams.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed 1 declare that what
I claim is
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1st. In a lantern, the form of revolving lantern body to be used in conjunction
with projecting apparatus as herein substantially described and shown.
2nd. In lantern Microscope P The special form of condensing lenses E. E.
Figs. 1 & 2 whereby the whole of the rays from the radient are utilized, consisting of
three lenses first; plano convex, second double convex third meniscus, the curvature
to be arranged as the focus requires, substantially as and for the purpose set forth.
3rd. In the Lantern Microscope The form of mechanical stage H. Fig. 3 with
set of wheel diaphragms I substantially as and for the purpose set forth.
Dated this 24th day of March 1888