HINTS ON RETOUCHING. I.--APPARATUS AND MATERIALS. The apparatus and materials required for retouching negatives are an easel, or rest, for the negative, a few pencils, a sable brush, two cakes of moist water-color, and a little retouching varnish. Retouching-frames may be bought of dealers in photographic supplies; but one which may be made at home, at a very small expense and in a short time, answers every purpose of the more expensive apparatus. [Illustration: T T, Table; E E, Edge of board; S S, Support; F, Fastener.] Take a piece of half-inch board twenty inches long and fourteen inches wide, and cut an opening in the centre just large enough to admit the largest size negative used by the amateur. Round the edges of this opening tack narrow strips of wood--cigar-boxes make about the right thickness--allowing them to project over enough to hold the negative after the fashion of a glass in a picture-frame. When a smaller size negative is used it is placed in a kit, and the kit fastened in the opening. Next take two pieces of wood twelve inches long, two inches wide, and half an inch thick, and attach them to one end of the board at the corners by hinges. At each side of the board fasten by a small screw, so that they may be moved easily, a small strip of wood having in one end a small hook. In the outside edge of each support fix a small staple or screw-eye, and when the board is wanted for use open the supports, hook the strips of wood into the staples, set the frame on a table, and you have as firm and solid a retouching easel as can be desired. The accompanying diagram will make the explanation clear to any one. Three or four of Faber's pencils, varying in softness from HHH to HHHHHH, will be needed. Cut them in long slender points, leaving at least half an inch of lead at the end free from wood. They must be ground to almost needle sharpness. A handy device for renewing the point when it becomes dulled is to tack a piece of fine sand-paper to a small block, and use it for rubbing down the superfluous lead. Two cakes of water-color are convenient, though they are not always used. Indigo blue and lamp-black in the moist colors are considered the best for this purpose. A very soft sable brush with a fine point is used to apply the paint. This brush must not be very long, but should be of medium thickness. Retouching fluid or varnish may be bought ready prepared, or it may be made according to either of the following formulas: Sandarach 1/4 oz. Alcohol 1-1/2 oz. Castor-oil 20 grs. Put the gum-sandarach in the alcohol and shake till thoroughly dissolved, then add the castor-oil. Shake well before using. Gum-dammar 35 grs. Yellow resin 3 drms. Oil of turpentine 20 oz.