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.)

A

Sodium Fluride

6 grains

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

4 ounces

B

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.)