SCIENTIFIC SUMMAEY. 
113 
same time a "bell rings to announce the completion of the exposure. The 
apparatus consists of a dial divided into certain spaces, under which a pen- 
dulum moves by electricity. This is attached to the camera, and when the 
operator has prepared his plate for exposure he places one of the hands of 
the dial at a certain point, and connects the pendulum, &c., with the galvanic 
battery ; he may then go away, perfectly satisfied that at the| time he has 
indicated on the dial the exposure will be terminated, and he will be sum- 
moned to remove the plate. 
Photography in Japan. — We are informed, that in the city of Osaka, Japan, 
there are not less than forty native professional photographers. 
Another New Dry Process. — The photographer-in-chief of the Abyssinian 
expedition will practice a new dry process, which he calls the cofiee process 
— the preservative being an infusion of coffee sweetened with sugar. 
When the plate is removed from the silver baths it is washed with water, 
and afterwards treated with the coffee, and then set aside to dry, ready for use. 
Neiu Panoramic Apparatus . — The well-known photographer, M. Camille 
Silvy, has recently taken out a patent for a new panoramic camera, by 
which four views can be consecutively taken upon one sheet of sensitized 
paper, by means of cylinders within the camera, by which the paper is 
pressed into contact with the convex side of a curved glass during exposure, 
wound and unwound so as to expose the whole of the surface to the action 
of light in the four exposures. For military purposes this invention pro- 
mises to be specially valuable. 
Neio Pocket Camera . — Mr. Thomas Sutton, B.A., editor of Photographic 
Notes, has suggested a means of converting an ordinary opera-glass into a 
photographic camera, by simply removing, for the time being, its object and 
eye glass. A dark slide might be made, perhaps of metal, of the usual 
form, having a shutter without hinges. When it was required to expose 
the plate, the slide would be put into a thin metal case having a round 
hole in front, with a flange into which the open end of the opera-glass could 
be screwed. The back part of the slide-case should also have an aperture of 
the same kind and diameter, through which the image on the ground glass 
could be viewed when it was in the place of the slide. The lenses might 
consist of a pair of doublets of different focal lengths, and a portrait lens, by 
which the photographer would be enabled to take any class of subject, 
whether instantaneous or slow ; and the three lenses would occupy but little 
room. The portrait lens would be about inch clear aperture, and would 
act very rapidly. An elastic disc, covering the hole in the back of the slide- 
case with a small single lens about 2-inch focus, would enable the operator 
to focus and render the image visible. A pocket tripod stand could easily 
be contrived to go with the new opera-glass camera. 
Plan for Preserving Negatives. — Mr. George Dawson has suggested an 
excellent plan for preserving negatives. After the negative has been 
thoroughly washed and dried, albumen is beaten up with a little hot water 
and applied to its surface with a large camel-hair brush. It is then set 
aside to dry in a place free from dust, and afterwards varnished with New- 
man’s varnish. 
YOL. YII. — NO. XXYI. 
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