The accompanying illustrations show a form of scribing block clip greatly in favour a few years ago, simply because turning, rather than fitting, was principally required. Fig. 1 shows the clip complete in elevation. It consists essentially of three pieces, the clip itself A, the square washer B, and the handle C. The clip is shown in plan by Fig. 2, and in end elevation by Fig. 3. It may be made from square steel, drilled with a twist drill at one end to lit the post, this end, the left in Figs. 1 and 2, being rounded off to suit. The sides of these holes having been face I on a mandril in the lathe, these edges can be placed on any true surface, and centre lines scribed across at the ends. Or the piece can be placed on a mandril, and, the rounded end being centred, the ends of the mandril resting in V-blocks, the point of a knife tool is set to the mark, the tool withdrawn by the bottom slide only, the piece turned round, and the point of the tool moved up to mark the other end. The top slide must not be moved in these operations. Of course, the ends should have been prepared for scribing previously by filing and chalking. This method will ensure that the turned and threaded part shall be square with the hole, the mandril and a packing piece under the shank end being used in drawing the cross centre lines. The rest of the work presents no difficulty, but the face at D (Fig. 2) should be turned back just past the hole, a collar being formed at E. The turning down of the shank at F is for ease in chasing the thread. G (Fig. 3) shows the slots left by the turning back at D (Fig. 2). Fig. 4 is a plan, and Fig. 5 an end elevation of the washer. The outer surface of this corresponds with the shape of the large end of the clip, and a recessed hole is bored in it, the larger end fitting on the collar E (Fig. 2), while the small hole slides over the threaded end of the clip. The washer is slit down the centre uearly but not quite to the bottom, a hole for the scriber having previously been drilled across as shown at the top of Fig. 1. The handle C (Fig. 1) is threaded to fit the screwed end of the clip. The cross section of the boss and of the handle itself is circular. The washer also may be circular instead of rectangular, and will then work easier on the post.

Fig. 4.

Fig. I.

Fig. 3.

Fig. 5. Clip for Engineers' Scribing Block.