To those who possess but little drawing ability a pantograph will be found of the utmost service for enlarging and transferring copies of designs from paper on to wood, such as is required for fretwork or inlaid work. The use of the apparatus will be understood from an examination of Fig. 1, which shows the apparatus complete.
This instrument is made almost entirely of wood. It consists of four perforated wooden limbs or rules A, B, C and D, and a block E. These limbs are arranged in pairs and jointed together at the crossing, the two crossings being jointed together at -Fand G. The perforations are made at uniform distances, in accordance with the scale of measurement. The pivoted joints by which the top pairs are connected are constant, while the joints between the two intersecting limbs of each pair may be shifted by inserting the joint pins H in different holes in each limb. By thus changing the pins the body may be reproduced in any scale, either larger or smaller than the original, or it may be drawn the same size.
In constructing, first make the block E from a piece of wood 1/2 in. thick, 5/8 in. wide and 2 1/2 in. long to the shape of Fig. 2. Now cut. the two limbs or strips A and B, Fig. 1, both 1 ft. 3 1/2 in. long, similar to Fig 3. At J drill a 3/4-in. hole for the pencil to fit; at the other end of the limb B drill a 1-16 in. hole; these holes must be 1 ft. 2 1/4 in. apart from center to center. The limb A must be similarly drilled with a 1-16 in. hole at each end. Now cut the other two limbs for C and D 1 ft. 5/8- in. long, and 3/8 in. from the end of each drill a 1/8-in in. hole for the tracing point, which can be made with a wire nail 1 in. long. When this is inserted one pair gradually decreases as the cut approaches the supported end. A recess in the inner wall, such as a port, will often cause considerable difficulty, but slow feeding and a light cut will usually overcome all such obstacles.
of limbs will be complete; the other pair are coupled in a similar manner. Each limb is 5/8 in. wide and 3-16 in. thick, and shown separate in Figs. 4 and 5; the perforations are shown in the illustration; each hole is 7/8 in. apart. The coupling pins are made from very fine screws. It will be convenient to mark the perforations as shown in Fig. 1.
When a copy is to be made the corresponding numbers on the limbs are put together. In use the end pivot E is placed in the block E, the pivot F sliding on the plane surface of the table according to the impulse given to it, then end hole J carrying the pencil, and the coupling of the two limbs C and D carrying the tracing point G. Lines traced by G will also be drawn by J on a larger scale, corresponding to the adjustment. If the copy is to be reduced, the tracing point is placed at J and the pencil at G. With the fingers of one hand on the tracing point, move it carefully over the design; at the same time with the other hand apply just sufficient pressure to the pencil to cause it to make its mark as it travels over the paper. All drawings can afterwards be shaded as desired.-"Work, " London.