This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Introduction. If one does not desire to go to the expense of purchasing a regular enlarging camera, it is possible to construct an enlarging apparatus that will answer the purpose and give practical and satisfactory results. The enlarging box may be built in a manner similar to the one shown in Illustration No. 18. For the camera you can use your regular view camera by removing the ground-glass frame, and by means of the brass clamps that attach the ground-glass frame to the camera, you can attach the camera to the enlarging box. Your enlarging box may be made stationary, if you so wish, and your camera made detachable so you can use it for other purposes. By merely unhooking it from the enlarging box and again attaching your ground-glass frame you have your view camera complete. For this enlarging box it is advisable to select wood that will not warp nor split easily. Of the cheaper woods obtainable, bass wood is recommended.
634. The cone (B) is made of one-half inch material, and for the 8 x 10 camera this cone should be made of four pieces of wood 15 inches long, 12 inches wide at the larger end, and 6 inches at the smaller. In fastening these boards together use No. 4 finishing nails, or long, thin brads. When the cone is completed the inside of the small end will measure 5x6 inches, and the cone should be fastened to the body of the enlarging apparatus so that the long way will be upright.
635. Now construct a frame (J) of either half inch or inch material, to be fastened securely to the large end of the cone. This is to act as a flange or casing to fit against the wall, and should, therefore, extend two to four inches beyond the cone, while the inside opening should be 10 x 10 inches in size. After fastening this flange or casing to the large end of the cone, construct a box 4 inches deep, which is to hold the ground-glasses ( C, D, E and F) and the negative (H). The inside measurement of this box should be 10 x 10 1/16 inches, the 1/16 of an inch being allowed to give a little play for inserting the ground-glasses and negative. In this box provide four grooves for the inserting of ground-glasses and one groove for the negative. A door (G) should be placed at the side and hinged at either top or bottom, as shown in the illustration.
636. The ground-glasses should, of course, be next to the cone, in order that the light may be diffused before reaching the negative. The grooves are supplied by nailing small strips of wood, 3/16 x 1/2 inch size, both on the bottom and the top of the box, 3/32 of an inch apart, or far enough apart to permit of the thickest ground-glass or negative being easily inserted and withdrawn. A narrow frame or casing (K) should now be fastened to the edge of this box, to which the camera (L) may be fitted. This should be carefully done, in order that no light escapes between the box and the back of the camera. A small flange may be readily attached to this box so as to fit into the back of the camera in exactly the same manner as the ground-glass back that comes with the instrument. In order to permit of enlarging from an 8 x 10 negative the opening in this flange should be 1/16 inch smaller than 8 x 10 inches.
637. A base-board should now be fastened to the whole apparatus, as shown in the accompanying illustration, so the camera and the balance of the apparatus will fit together perfectly. A careful study of the illustration will enable anyone, handy with tools, to construct this instrument at a cost of not over $1.50. An 8 x 10 view camera is an excellent one to employ in conjunction with this home-made instrument, for with this size camera any size negatives may be enlarged from, up to, and including, 8 x 10 inches.