It is sometimes desirable to have the name of a picture marked on the negative so that it may appear in the finished print. This may be done in several ways. One of the simplest is to write the name backwards in India ink on the film side of the negative. This should be done with a fine drawing-pen, and the lettering made in one of the lower corners. As the title appears white in the finished print the writing should be done where the glass is clear or in the deepest shadows. To have the name appear in black on the print, take a fine steel needle, and having first marked the letters lightly with a pencil, scratch the letters through the film to the clear glass. Make the edges smooth, and see that the lines of the letters are perfect, as every imperfection in the lettering appears in the print. One should always put his initials on a good negative. They can be put on either in India ink or scratched through the film. If one does not wish to write the name on the negative it can be written on the sensitive paper before the print is made. India ink is to be preferred, but good black ink will do. The ink will wash off in the toning solution, leaving the name clear and distinct on the print. An ink for writing on photographic prints may be made by taking 2 ounces potassium iodide, 6 ounces distilled water, half an ounce gum-arabic, 1-1/2 drams iodide. This is used for writing on the dark part of photographic prints. SIR KNIGHT JAMES G. ZIMMERMAN sends a photograph of a flash of lightning, and wishes to know if the picture is printed right, if there is any use for such a photograph, and if it is necessary to have it copyrighted before having it reproduced. The printing of the picture is correct. Pictures of this kind are useful for meteorological purposes. It was not till the introduction of instantaneous photography that the shape of a flash was known. Artists always drew pictures of a lightning's flash in zigzag lines with sharp angles, whereas instantaneous photographs prove that the electric fluid forms a curve and never an acute angle. The enclosed picture is an excellent one, and shows several distinct loops in the line of the electricity, something very unusual. It is not necessary to have a picture copyrighted before having it reproduced. The use of the copyright is to protect the owner of the picture from others making use of it without his consent. SIR KNIGHT ERNEST BRIGGS asks for a formula to use with under-exposed plates. Sir Ernest will find formula in No. 839 (November 26). SIR KNIGHT JAMES H. HARTLEY, 33 Temple Street, Paterson, N.J., says that he would like to exchange prints with other members of the club, and that he has some good views of Passaic Falls. Sir James is informed that his first request, which he says he sent some time ago, did not reach the editor. ADVERTISEMENTS. Arnold Constable & Co