Use Morgan and Kidd's ordinary enlarging paper for negatives, and a Rouch's patent 10 by 8 camera with an ordinary dark slide, in which fix slips of copper 3/8 in. wide for the paper to rest on. Lay a sheet of sensitive paper face down, then a sheet of opaque orange paper, then another sensitive paper, and so on, alternately, until you have 10-16 sheets of each kind, and on top place a sheet of glass to keep them flat.
The exposure is long - being about the same as for a wet plate. After exposing, place the dark slide in a changing-bag 28 in. by 12 in. by 5 in., made of 3 thicknesses of twill, and having sleeves in the 5-in. sides near one end, and a slit at the other end, which rolls over and is covered by the focussing-cloth, and is perfectly light-tight. Remove the exposed sheet, and the opaque paper next it, and place them at the back of the glass, which operation takes less than a minute, and can be done anywhere.
Pyrogallic acid .. .. 4 gr.
Ammonia bromide .. 2 1/2 gr.
Ammonia ...... 6 drops
Water........ 2 oz.
Turn the paper face upwards, and pour off the water, when the paper will be quite flat. Pour on the developer, and the details should be out in 1 minute at the most; but care should be taken not to push the development too far, as the shadows should be quite white. Wash, fix for 10 minutes in hypo 1 to 5; wash, soak for 10 minutes in a saturated solution of alum, and wash again. If the negative is stained yellow, use 10 oz. saturated solution of alum, 1/2 oz. citric acid; after which, wash.
There are 3 ordinary ways of making the paper transparent: - (1) With white wax, as in the old paper process. (2) 4 parts castor oil, 1 part ether, brushed on the back; then warm, and when cool, with a rag take off the superfluous oil, and warm again. (3) Brush over the back of the negative a mixture of 1 part Thomas's rubber solution, 1/2 part pure benzole, 1 1/2 part Canada balsam. 10 by 8 plates weigh 8-10 lb. a dozen, including packing, whereas 9 doz. paper negatives weigh less than 4 lb., which makes an immense difference. Then, with one wet plate, slide, and a changing-bag weighing a few ounces, you can take 12-16 negatives; the whole set of apparatus taken in the field weighing only 12-15 lb.