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534 THE PHOTOGRAPHIC NEWS. [August 21, 1885. potassic oxalate must have dissolved all it is capable of dissolving. For this reason it is well to keep stock bottles of each solution, to which sufficient ferrous sulphate in the one,and potassium oxalate in the other, is constantly added, to keep the bottles half full of crystals; the remainder being full of the solution. If not much work is expected, it will be well to place a small crystal of sulphate of copper in the sulphate of iron bottle. This prevents the deposition of the ferric salt; but even this precaution is needless if the solution be used up within a month of making. Another precaution which must be observed, is to measure out the potassic oxalate first, and to add to that the iron solution, otherwise the liquid becomes turbid through the sudden precipitation of ferrou. oxalate. The quantity of solution required for the development of a picture will vary somewhat with the size of the dish used for development, as well as with the size of the plate. The plate must be entirely covered, and for this purpose a quarter-plate will require at least one ounce of developer ; a half-plate, two ounces ; and a whole-plate, four ounces. The solution having been poured into the dish, the exposed plate is taken out of the dark back, and quickly placed under the solution, gelatine side uppermost. The dish must now be kept rocked continuously, to ensure evenness of development, for about five minutes. The high-lights will now probably begin to appear as hard black patches. When this takes place, rocking may cease, and the dish should be covered over with a slate or other opaque body, and allowed to develop slowly for another five minutes. If, on examination by transmitted light, the half-tones show sufficient density to print, the develop ment may be stopped by washing ; if not, the plate should be returned to the developing dish, again agitated, aud again allowed to repose for five or ten minutes. It will sometimes be found necessary to leave a plate for half-an-kour in the developer. No harm will accrue from this, provided the developing dish be kept covered, to exclude any adventitious rays of light. The reason why it is better not to agitate the solution during development (as soon as the plate is thoroughly wetted) is, that the resulting picture is less hard if the development be thus conducted. An under-exposed picture has a tendency to hardness, as there are only high-lights and deep shadows ; but still development tends to soften this contrast. If half-an-hour’s development should fail to bring out the middle lights, then in all probability the picture has been hopelessly under-exposed. As a last resource, a fresh oatch of extra strong developer may be made up as follows :— Saturated solution of potassic oxalate .. 4 parts Powdered ferrous-oxalate 1 part Agitate together for a few minutes, allow to settle, and pour off the clear solution for use. A picture which will not “ come out ” under the influence of this developer has not received sufficient exposure to give a negative with any developer. CYCLING AS AN AID TO PHOTOGRAPHY. BY HENRY STURMIEY, (Editor of The ’Cyclist.) .So far I have spoken only of tricycles as made for ordinary purposes, and have pointed out, to the best of my ability, the most ready means of rendering them suitable to the wants of the landscape photographer. I now proceed to treat of machines specially designed and built specifically for photographic purposes, though in this direction but little has yet been done by manufac turers ; though I think a little healthy competition in this particular would prove not only useful to the photographic world, but also remunerative to the enterprising manu- • Continued from page 508. facturers who succeeded in producing the most practically serviceable and useful article. What is required by the professional photographer is a machine especially designed to fulfil in the highest degree the wants of his profession, and yet be adaptable for other uses, and short pleasure runs at will, and not rice versa, as is now the case. Comparatively few amateurs who go out on photographic tours on the tricycle of a week or more duration develop their plates each evening as they go, the reason being a lack of the requisites wherewith to do the same ; and the man who readily provides them with these will reap the benefit. I may here, however, give a hint to cyclists, that may come in useful. It is this: that they need not trouble to carry a special lamp with them, for their regulation “ King of the Road ” cycle lamp will do as well. I tried the experiment last summer and found it answer admir ably, developing several plates at night in a friend’s coach house by its light. What I did was to carry a piece of non-actinic paper and an india-rubber band. When I wished to develop, and had made everything ready by the full light of the lamp, I placed the centre of this paper against the lamp glass, and then passed the rubber band over the bell front, carrying the paper with it; the sides of the paper I folded round the sides of the lamp, so as to intercept any rays that might eome from corners or air holes. I used two thicknesses of paper to make assurance doubly sure. As a matter of fact, the paper I used was that in which the dry plates were wrapped, though that, perhaps, would not be safe in all cases. To revert to the machines, the “Photographic” tricycle introduced this spring by D. Rudge and Co., of Coventry, is simply an ordinary “ Coventry Rotary,” fitted with a specially constructed holder for carrying the camera and slides, and with Cusson’s patent arrangement in lieu of a tripod. This mechanism is suitable to no other machine, and for one who rambles about seeking what he may devour in the way of views cn route, it is well suited. It consists of an attachment to the steering handle, in which a brass tube slides up and down, at the top of which the camera, working on a swivel joint, is placed. When in the field the camera is carried thus, and at any moment, without leaving the saddle, the cyclist can halt and turn his lens upon any object that may strike his eye, his plates being all ready to hand in the box at his back. The camera has a considerable range of vision, and can be raised or lowered some inches at will. The machines shown by the Coventry Machinists' Company, at the Amateur Photographic Exhibition, can hardly be termed special photographic tricycles, as the chief special arrangement is in the sockets for holding tripod, &c. The only other firm that has shown any desire to cater especially for photographers is Singer and Co. (Challenge Works, Coventry), who, in the spring of 1884, placed a machine,on the market which was, and is, the best of its kind for heavy work, and professional landscape workers ; and my only wonder is that they have not pushed it more than they have, as, after the first one or two shown at the Exhibition at the Agricultural Hall, we seem to have heard but little of it. It belongs to a class of tricycle of which there are now several examples, but which was first introduced by Singer and Co. I refer to the “ Carriers,” a strong type of machine especially built for the purpose of carrying goods. More than one make of this type of machine could readily be converted to this especial use; and as a class they may be taken as being well suited for photographic work of a heavy nature. “ Singer’s Photographic Carrier" is a machine of this variety, and of it 1 hear good ac ounts, with one of which I will conclude this already lengthy article. “ An ounce of practice is worth a pound of precept," is an old maxim, and I have no doubt that the experiences of Mr. H. Hughes, a professional photographer of the city of Coventry, will. speak far better than can any words of mine, not. only as to the merits of the particular tricycle
