An aid in Tarnishing lantern slides made from negatives or in varnishing photographic negatives themselves is illustrated by Figs. 1 to 5, the letter references in these figures being similar. It is usually advised to heat the slide before a fire or lamp before flowing the varnish on and off ; in too many cases this means unequal heating and burnt fingers. With this hot box it is only necessary to lay the slides on the top, fill the box with water (boiling or cold), and light the spirit lamp, and in a short time the slides will be heated equally all over. After varnishing, they are left on the top until thoroughly hard and dry. The box consists of eight pieces of wood screwed together, supporting a zinc box with an iron top. The front and back pieces A and B are each 17 in. by 6 in. by 3/4 in. The two side pieces C and D are each 14 in. by 6 in. by 3/4 in. These four pieces are mitred at the angles, chamfered on the top edge, and screwed to the angle pieces E, F, G, and II, each 4 in. by l in. by l in., on which rests the zinc box. The front piece has an opening cut in it to admit the lamp L, and the back piece has two pieces cut out to admit the water inlet J and the steam vent K. The hot box is l5 in, by 12 in. (this allowing 1/4 in. space between it and the wood) and 2in. deep.

It is made of stout zinc with an iron top 3/16 in. thick soldered on, forming a level bed for the slides. The water inlet discharges on the floor of the box, and the steam vent is taken from under the top plate as shown. Steam issuing from the water inlet indicates that more water is needed. This box will take one dozen lantern plates and, as has been stated, is equally as well adapted for use in varnishing ordinary photographic negatives.

Hot Box for Photo Negatives and Lantern Slides.