NEGATIVE NUMBERER.—An arrangement for numbering negatives. The most ingeni ous form is that devised by Kruse, of Berlin, and which is thus described :—A small benzine light (or candle) is placed in a metal lantern, so constructed both with regard to the admission of light and the letting out of smoke that no white light can escape. On the outside of this box in the right hand corner, there is a groove cut, into which the unnumbered exposed plate is inserted. This slit is covered by three small hoops of thin copper sheeting placed together. Two of these hoops or bands have on them the number oo up to 99, third one has from o to 9. These numbers are cut out like stencil plates, so that by a judicious turning of the bands the numbers 00000 up to 99999 can be seen on looking through the slit. The turning of both these bands, which, num • See Chapman Jones's " Science and Practice of Photography."
tiered from oo to 99, form the last four figures, is caused by moving a button up or down, by which means the bands referred to are wound off from one small wooden cylinder on to another, whilst the band bearing the numbers o to 9, which indicate the ten thousandths of the number, is changed by every movement of the band from io to io thousand numbers. In using the in strument the light is shut off by means of a red glass, brought to view from within when looking for the controlling number, the undeveloped plate is inserted in the before-mentioned slit, and then by a sudden turn the red disc is drawn away. The exposure for the number is thereby completed, and the latter appears in the development black upon a bright ground. The ap paratus may also be used for printing names, titles, or dates on the negative.