H. W. HALES. Examples showing the greater light efficiency of the focal plane shutter as well as its usefulness for ordinary and move ment work. as flying birds, race horses in motion, etc., are easily obtained. Even for tripod work much of the valuable time of the operator can be saved by opening up his camera, looking at the view and then if he decides to take it (using his tripod) do So. This advantage alone is very great and no one who once gets used to this will ever be satisfied with any other way. Much has been said and written about focal plane photography in Europe where a special study has been made of this class of work for years, but in this country it may be said to be only in its infancy, and while there are a larger number now taking it up there is no doubt that much more may be done to advantage, and there is a large field for the intelligent and careful worker, especially if he is thoughtful and painstaking. One caution is necessary in order to work the focal plane camera to advantage and that is not to use too high a shutter speed to start with. Learn to know somewhere near what speed your object requires and endeavor to give it all the time consistent with the subject. Almost all new workers in this line use too high a speed at first as it seems so fascinating to the average worker to be able to use the high speed, that he uses it whether it is necessary or not. Bear in mind that although the light intensity of the focal plane shutter is far superior to any other, still there is a limit even to this, and it is not desirable to have an under exposed negative if it can be avoided. It is better to show even a little motion in the picture rather than to have a negative that is worthless on account of insufficient exposure. From these few lines the reader will see that much may be done in this field of photography and the general interest cannot help but increase with the worker's knowledge and experience. The pictures accompanying this article have been selected from a large number not as extreme examples of focal plane work but rather to show the general or all around adaptability of cameras of this type and to show that they can not only do all that any other type of cameras can do but that work can frequently be obtained with them that could not be had in any other way. HE summer of 1906 found me on the coast of the Gulf of Mexico, and notwithstanding the remoteness of the situation I was frequently called on to make portraits and develop films for summer visitors. My first call found me without sulphuric acid or chrome alum, therefore an acid fixing bath was out of the question. Ice was twenty-five miles away and had to be handled by five. different carriers to reach one's wharf, therefore its price was prohibitory, average temperature after sundown 85 to 90 degrees. Water freshly pumped was 70 degrees. Running water, as from a tap, was not obtainable, and soon after pumping got to air temperature. These were the conditions; not much worse as to temperature than frequently obtained in northern districts. I could not take advantage of morning coolness as my dark room was not dark. My method at first was to take advantage of every scrap of coolness to be had, although later experience showed that extreme precautions were not necessary. For instance at first I put the hypo crystals into the dish, and only when I was about to begin development did I pour freshly pumped water in, thus I had a cool solution caused by the dissolving of the crystals. It is a fact not generally known that recently dissolved hypo has a somewhat astringent effect on the film, while the same solution used next day has a positively softening effect on the film. The problem of holding the film intact is about the same as developing it: there are two opposing principles in the developer; one is an astringent or hardener, viz., pyro, the other is a softener, viz., the carbonate of soda. As the amount of the astringent is comparatively small, usually two to three grains per ounce of solution, and as the softening agent is much greater, four to eight grains per ounce, it stands to reason that to keep the film on the plate the softener must be held down in some way. In places where it is possible this is done by regulating the temperature with ice. But there are many places where ice is not obtainable and the solution of the problem is to be looked for in an accelerator which does not soften the film. These requirements are found in formaldehyde, a very powerful astringent, antiseptic and deodorant, sold in 40 per cent. solution by all druggists. This solution can be substituted entirely for any other accelerator, but I prefer the results obtained by using a little over one-half the carbonate of soda called for by the formula and two drops of formaldehyde to each ounce of developer. In some cases a small amount of bromide may be necessary, say one drop of a ten per cent. solution to each ounce of developer. The formula for developer which I adopted is as follows: Water 4 ounces Sulphite of soda, I mustard spoonful, about.. 20 grains Dry pyro, I mustard spoonful. .6 to 8 drops 10 grains It may seem strange to measure by mustard spoonfuls, but |