Before taking up my work with the Eastman School I had to thoroughly familiarize myself with both the theory and practice of tank development and the further I pursued my investigations the more fully I became convinced of the practicability of the Eastman Plate Tank, not only as a producer of first class results but from the standpoint of economy as well - to say nothing of its convenience and comfort.

Not long ago I had a gentleman tell me that he had purchased a tank but had not used it, as he was afraid to - that he did not have sufficient confidence in it to entrust his regular run of work to it. This reminds me a good deal of the time when dry plates were first introduced, and how slow the photographers were to make use of their many advantages - you don't find many of the profession using the old wet plate to-day - and soon tray development, except for the extra large plates, will be equally obsolete.

Now let us make a few practical comparisons between tank and tray development.

You go into your dark room with a dozen or so of plates to develop. You mix up your developer and place, say a dozen plates in a big tray and pour the developer over them. In your big shallow tray a good proportion of your developer is exposed to the action of the air, and in a short time it decomposes and oxidizes - and if during development you remove a plate for examination, it will acquire density in the high lights even more rapidly than if left in the tray, owing to the increased action of the oxygen in the air. In cases where the negative under examination happens to be a trifle under-exposed, say a girl in a white dress, what do you do the moment that white dress begins to get strong - you say, "I dare not let that go any further, because if I do there will be no detail in the high lights," so in it goes into the fixing bath and when you remove it you find you are without detail in the shadows.

That demonstrates one great advantage of the tank; but a very small portion of the developer is exposed to the action of the air, it has but little chance to oxidize, and at the end of the half hour's development the solution will be almost as colorless as when first made up, and further, your solution being more dilute than that for tray development, allows the reducing action to proceed slowly and equally, building up the detail in the shadows equally with the development of the stronger portions of your negatives.

Now here is another little point I want to impress upon some of the skeptical. You say, I live in a very hot or very cold climate, and while the people in the more temperate parts of the country will have no difficulty in maintaining the proper temperature of the developer, how can I do it without going to more trouble than it is worth?

From A Nepera Print By J. E. Ralston Seattle, Wash.

From A Nepera Print By J. E. Ralston Seattle, Wash.

We had a session of the School in El Paso, Texas, and the thermometer registered 110 degrees. I made up the developer and placed it in the tank with the correct temperature of 65 degrees; at the end of the half hour the temperature had increased but three degrees, and this increase had been so gradual as to produce no noticeable difference in the density of the plates. In a very cold climate, it is still easier, you can easily bring your developer up to the correct degree by adding warm water, and as soon as your plates are in the tank, you can remove the whole business to a room that is heated to a normal temperature.

The best way I can explain why the temperature of the solution varies so slightly when sealed up in the tank during development is this: my mother, and I guess most everybody else's mother, has put up fruit and preserves, cooked them boiling hot and then placed them in Mason fruit jars and sealed them up tight - and I have more than once waited all day and half the night for them to cool off enough for me to get a taste.

Now a word as to the economy of tank development. I have frequently been asked "how much more developer do you use?" You do not use any more developer to develop a dozen plates in the tank than you do when using a tray. You would not think of going into your dark room to develop two or three plates, as you frequently do, without using at least one ounce of your sulphite solution, one ounce of your carbonate solution, and one ounce of your pyro solution, together with eight or ten ounces of water. Now with the tank we use exactly the same quantity of chemicals, but instead of using eight or ten ounces of water we use sixty-four, and we can develop twelve plates just as well and a whole lot easier than you can develop the two or three.

With the tank you can develop sixteen dozen 5 x 7 plates with one ounce of pyro. That sounds like a large statement but here is the arithmetic: according to the formula used with the tank, your pyro solution is made one to sixteen, and you use just one ounce of this stock solution for each dozen plates. Looking over my note book I find this question has been asked a good many times: "Can the developer be used over again for a second lot of plates?" I will state that it can, but in such cases you must be sure your plates are all fully timed for this reason: during the first development the developer has taken up sufficient bromide of silver from the first lot developed, to act as a restrainer, just the same as if you had added bromide to your developer. Developer is cheap enough, however, to throw it away after each batch of plates has been developed.

In another issue, if the Editor permits, I will avail myself of the privilege and take up some other features that have done so much to popularize the Eastman Plate Tank.