ON drawings where the lettering is considerably scattered and some degree of uniformity is desired, it is quite essential that some rapid means be provided for drawing the pairs of parallel guide lines. Measuring is altogether too slow. In most drafting rooms will be ' found one of those rather large, obsolete, right-line pens. Cut off the points, as shown in Fig. 1, insert two chisel-pointed leads, and tighten the screw. When adjusting the distance between the leads it is .only necessary to partially loosen the screw, after which the leads may be pushed in or out. This instrument is very rapid, and requires infrequent sharpening. Fig. 2 illustrates another method of accomplishing the same end. A piece of transparent celluloid is provided with a series of slots of different widths. Although this little device is common, it is not to be found in any of the catalogues. It is superior to Fig. 1 where the lettering must not only be uniform, but of certain standard heights. The writer has used several excellent forms of A home-made ratchet drill. to a U-shape as shown at C, and drill a hole in the end of the U-shape iron, so it will be a neat sliding fit over the spindle B. A hole must also be drilled in the outer end of strap iron, so that a piece of round Iron or pipe can be screwed in position so as to ad as a handle, shown at D. A dog, E, is pivoted upon a pin, F, and a spring, G, holds the dog against the Drafting room kinks. lighting fixtures for the drafting table, but none that gave more satisfaction than the little light shown in Fig. 3, which was improvised in the course of a half-hour from a piece of heavy copper wire and a paper weight. On one end of the copper wire a hook is formed. The wire then curves downward toward the base, Where it is bent into a rectangle the size of the paper weight. The extra length of wire is then carried upward and neatly bound to • the vertical section. Two pieces of cord serve to connect the wire securely to the paper weight, and also to keep the base from scratching the table top. The electric cord in leaving the socket is fastened to the hook, from which it may be run directly to the outlet, or else down the curved copper standard and once around the knob on the paper weight. The latter is the better method. A shade of Bristol board answers every purpose, and the resulting lightness of this feature, as well as the upper works in general, renders the lamp very stable and easy to shift. For those who have too little office space to accommodate the usual horizontal blueprint tank and yet find it necessary to make a few prints occasionally, the vertical tank shown in Fig. 4 will be convenient. This need be only an inch or two in thickness, so that the space it occupies is negligible. One or more wires running longitudinally across the top will serve-to hold the prints while washing. The writer has seen a print two by three feet washed in one of the stock metal tubes used for keeping blueprint paper. These tubes are about two and a halif inches in diameter and have screw tops. In Fig. 5 is a suggestion to draftsmen who have to use special curves very frequently. A piece of transparent celluloid, which may be obtained at most stationers, is placed over the pencil outline of the desired curve, which is then marked off. The curve is then cut out with the shears and smoothed up with file or sandpaper. A piece of cardboard will serve to keep the celluloid far enough away from the paper to permit the use of the ruling pen. There are comparatively few draftsmen who fully appreciate the possibilities of the ordinary flat machinist scale. With a little practice this form of scale may be readily handled on edge in which position spacing may be done with almost mathematical accuracy, as a sharp pencil point fits into the small grooves that mark the distances on the scale. In fact, there is probably no other method by which a point can be placed accurately and quickly. Supposing that in Fig. 6 it is desired to subdivide the space between the two parallel lines into thirteen equal parts: Simply .place the scale at a suitable angle to the parallel lines so that thirteen equal divisions— in this case quarters— exactly reach from one line to the other. Run the pencil point down each quarter mark, and the spacing is done.
This article was originally published with the title "Drafting Room Kinks" in Scientific American 105, 6, 124 (August 1911)