Three distinct methods of photo-engraving are employed in the United States, viz.: swelled gelatine, photo-etching, and wash-out. The latter is known as photo-electrotyping. The first steps to produce a plate by any of these processes are exactly alike, _i. e._ a perfectly sharp negative, either in line or stipple, must be produced. If the copy furnished is a wood-cut, steel or lithographic print, in which the lines are absolutely black on white paper or card, the negative is made direct and no drawing is necessary, unless a very great reduction is required, when it becomes necessary to make a drawing, the lines of which are made open enough to stand the necessary reduction. Where the copy furnished is a photograph, or wash drawing, it is first photographed one half larger, or, where fine work is desired, twice the size the plate required. In cases where exceptionally fine work is required it is even made three times the size. The photograph thus obtained is technically termed a silver print, and is an untoned print on plain paper. On this silver print the artist makes his drawing, using the best India ink, which must be so black that the finest hair-line, when examined through a magnifying glass, appears absolutely jet black. After the drawing is made, an alcoholic solution of bichloride of mercury is poured over it, and quickly washed under the tap, leaving the drawing on perfectly white paper. The artist then does whatever retouching may be necessary, and the drawing is ready to be photographed. The advantages of this method of drawing are apparent. The artist, being able to work directly on the enlarged photograph of the object, obtains absolutely correct outlines and detail. The drawing, when finished, is sent to the gallery, where it is photographed to the required size of the plate. The focus of the camera is carefully adjusted with the aid of a focusing glass, so that the negative resulting will be perfectly sharp. This must be carefully done, for unless the negative be sharp a perfect plate cannot be obtained by any process. The sensitized collodion plate is exposed in the camera from one to six minutes, after which it is taken again to the dark room, developed, and fixed. It is then intensified until the portions representing the whites of the picture are perfectly opaque. Up to this point all the processes are alike, and the differences from here will be noted.