Have ready two graduates, one containing 6 drams of the stock developer, the other 2-1/4 ounces. Begin counting seconds upon immersion of the plate in the weak developer and watch for the outlines of the image, not considering the sky. If the time of appearance is less than 40 seconds, add the smaller quantity of stock solution; if more, add the greater. The total times of development are given in the following table. Cover the tray for protection from light as soon as the solution has been modified properly. ==================+==================+======================= TIME, IN SECONDS, | QUANTITY OF | TOTAL DURATION OF OF APPEARANCE | METOQUINONE | DEVELOPMENT, INCLUDING OF IMAGE, | STOCK SOLUTION | TIME OF APPEARANCE. DISREGARDING |TO BE ADDED AFTER |---------+------------- THE SKY. | IMAGE APPEARS. | Minutes.| Seconds. ------------------+------------------+---------+------------- 12 to 14 | 6 drams | 1 | 15 15 " 17 | " | 1 | 45 18 " 21 | " | 2 | 15 22 " 27 | " | 3 | 15 28 " 33 | " | 3 | 30 34 " 39 | " | 4 | 30 -------- | ------------ | -- | --- 40 to 47 | 2-1/2 ounces | 3 | Over 47 | " " | 4 | ------------------+------------------+---------+------------- As soon as development is finished rinse the plate briefly, immerse in equal parts of the reversing solutions and carry the tray into bright daylight. Gradually the image clears and the true colours are seen by transmitted light. In three or four minutes the action will be complete. Rinse the plate in running water for thirty or forty seconds and immerse again, still in daylight, in the developer. In three or four minutes the white parts of the image will be seen to have turned entirely black. The plate may now be rinsed for three or four minutes in running water and set away to dry without fixing. To avoid frilling in summer, it is well to immerse the plate for two minutes after reversal in Water 5 ounces Chrome alum 25 grains After a brief rinsing proceed with the second development as usual. The completed transparency may be protected from scratches to a certain extent by varnishing the film side, although this is not necessary. The varnish consists of Benzole (crystallizable) 5 ounces Gum dammar 1 ounce It should be applied cold in the usual way, making sure that the entire surface is covered, and then setting the plate on edge to dry. The other colour processes now used with success also are based upon the colour screen.