Hammer's Non-Halation

Is a Double- Coated Plate.

859. The cleaned glass is first coated with our Slow emulsion and dried as usual; then each plate is examined for any possible defects. The perfect plates are returned to the coating-room, and there receive a second coating, but this time it is of our regular Extra Fast emulsion. They are then returned to the drying-room, dried, and the next day again examined. Those having no defects are then packed for the market.

860. One can readily see the immense advantage this plate has over a single-coated plate for general work as where great contrasts are to be photographed.

861. Expose (time) for the shadows, time the exposure for the outer film; the under or slow film will take care of the high-lights. To get the best results these Non - Halation plates should be developed with a rather dilute developer - give the under film a chance to show its quality. Fix, and wash a little longer than usual.

Weights And Measures Fluid Measure. 862

60 minims

1 fluid drachm

8 drachm

1 ounce

16 ounces

1 pint

8 pints

1 gallon

All chemicals are usually sold by avoirdupois weight; in which there are 437 1/2 grains to the ounce, and 16 ounces to the pound. This is the ounce used in all of our published formulae.

863. Stripping Film.

(Removing film quickly from glass.)


Sodium Fluride

6 grains

Water ...................

4 ounces


Sulphuric Acid

6 drops

Water ...................

1 ounce

Both solutions can be used until exhausted. Place the negatives in solution A for a couple of minutes, and then place directly in solution B. After another couple of minutes raise the film with the finger from one corner; it will soon leave the glass. Very good in the case of broken negatives, for transferring the film onto another glass. In this case place the negative (before stripping) in a chrome-alum bath, made up 1 ounce chrome-alum and 20 ounces water, for one-half hour. Then wash well and proceed to strip. (Another satisfactory method is given in Vol. X, page 331.)