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Mat 16, 1862.] THE PHOTOGRAPHIC NEWS. 231 lopment. But it must be remembered that these are not the subjects to tax rapidity. The pure light of Jersey is not that of smoky cities. M. Soulier, in a conversation we had with him recently, insisted emphatically on this fact, that street scenes are the real tests of instantaneity. Mr. Eng land’s successes have been in the streets of Paris, and some of Mr. Blanchard’s in the streets of London, and it is here they test the value of bromides. Mr. England informs us that he has spent many months in experimenting on this subject, and his conviction is that, cater is paribus, bromo iodized collodion with iron development is three times as rapid as simply iodized collodion with pyrogallic acid deve lopment. Our own experience has led us to believe that there arc certain conditions occasionally attainable in which simply iodized collodion and pyrogallic acid development will give as good and rapid results as it is possible to desire; but these conditions are difficult to attain and impossible to preserve; whilst with bromo-iodized collodion and iron development there is no difficulty. Mr. Sutton is a skilful manipulator, he manufactures his own collodion, which is as good as can be made, and he works in a Jersey light: we can understand how it may happen, as we know it does, that he is pre-eminently successful with the iodide alone. As regards the influence of bromides generally, we think he is in error, and we have the universal practice of American photographers, Continental photographers, and the most eminent photographers in this country in favour of our position. • •—•—- REMARKS UPON SOME OF THE APPARATUS EMPLOYED IN PHOTOGRAPHY* BY F. B. WINDOW. BATIIS and Differs (continued). The Horizontal Dipping Bath.—The vertical bath which I have just described is so universally used in this country, that 1 do not think horizontal baths, intended for sensitizing collodion, or other plates, were even manufactured for sale in this country until within a few weeks of the present time ; and yet, although they are inferior in some few points, which I will presently investigate, for general business purposes, they have so much to recommend them, especially to the amateur, that it is a matter of surprise to me that their use has been hitherto so neglected. There are two kinds of horizontal baths. Those in which the plate is placed collodion side upwards, and those in which the plate lies with the collodion side downwards. The description which follows refers solely to the last. The first-named baths, or those in which the collodionised plate is laid film upwards, are convenient, and, I think, to be pre ferred to the vertical bath, especially for large plates, on account of the small quantity of exciting fluid required with them, but in practice they are found to be inferior to the other kind of horizontal bath, and I shall, therefore, con fine my remarks to these latter. I should mention, how- ever, that the first are extensively used on the Continent, for all purposes. A plate is sensitized in a vertical bath by plunging it into a vessel containing the exciting silver solution. In a horizontal bath, on the contrary, it is laid, face downwards, on the silver solution, in the same manner as positive paper. A horizontal bath is a tray about a quarter of an inch larger each way than the plates that are to be sensitized in it, deeper at one end than the other; at the deep end the corners are filled up to the same level as the bottom of the shallow end, so that a plate laid in it may rest horizontally, one extremity upon the bottom of the bath at the shallow end ane ? he other upon the two corners of the deep end. . u cient liquid is used just to cover the bottom of the * Continued from page 221. shallow end, and the two corner pieces. Fig. 21 gives the plan of such a bath, and fig. 22 a section of it the dotted line in fig. 22 showing the level of the bath liquid. Fig. 21. Fig. 22. A horizontal bath may also be made with the bottom parallel to the edges, but curved, or hollowed out, in the sense of the length, so that a plate, when lying in it, may rest only on the edges of its sides. Practice has, however, convinced me that this is less effective than the one I have just described, as the film has more intimate contact with the bottom of the bath, and has a greater risk of being dis turbed than when it merely touches the corners at two unim portant points. The handy photographer can make a horizontal bath for himself, or, in default of tools, he can have one made by a carpenter in the following manner :—Take a piece of plate glass a quarter of an inch larger each way than the proposed bath, and set it in a wooden frame a quarter of an inch broad and an inch deep, like a boy’s slate; only, instead of making the grooves, which are to hold the glass in the side pieces, parallel to the edges, let them be cut so as to give the required inclination to the bottom of the bath (fig. 23). Fig. 24. Tig. 23. These grooves should be about an eighth of an inch in depth. The corners are then to be filled up with a piece of wood fastened in with cement, or, what is better, a silver wire may be fixed across them at the proper level. Lastly, all the woodwork inside and out must be thoroughly well coated, and the joints well stopped with hot rosin cement. Such a bath will cost about one-sixth of a porcelain vertical dipping bath, and is equally efficient. A temporary horizontal dipping bath may be made with an ordinary washing tray, whether of glass, porcelain, or gutta-percha, by filling up the corners at one end with some substance inactive to nitrate of silver—a piece of sealing- wax is always handy and is easy to fix by heat—and tilting up the other end, by placing a wedge under it (fig. 24). To use a horizontal dipping bath sufficient silver solution,
