This section is from the book "Amateur Work Magazine Vol6". Also available from Amazon: Amateur Work.
This is a box which is both useful, amusing and educational. With it any word of three letters can be formed, and it can be set "to open by forming one particular word.
The box may be turned from good sound wood, and is composed of three parts, a cylinder with raised band in center, and two lids. These are shown in Fig. 1, A A being the two lids, and B the band of cylinder. Fig. 2 is a sectional drawing showing the thickness of cylinder and lids and also illustrating the interior mechanism. C is a rod screwed firmly into center of top lid. D is a fiat disc with bent prongs under it, as shown, and having two slots at its outer circumference, through which F F can pass. F F and the slots are shown by Fig. 4, which represents D. E is another disc with a washer under it of sufficient thickness to keep it in position so that the prongs of I>, after passing through two slots in E, may work freely under It. E, together with the washer, is screwed down to center of lower lid. The lid and E with the slots, is shown by Fig. 3.
A groove is made round the cylinder at G, and a hole is bored at each end of the lower lid at G G, and into each hole, while the lid is on the cylinder, a peg is in serted, so that the lid may be revolved, but will not come off. It will be seen upon studying this mechauFig. 2. brought into position so that its slots will pass b' F, and F being turned by the lower lid must be brought into such a position relative to D that it will allow of the prongs passing through its slo1>.
Fig. 3. Fig. 5 shows a set of three alphabets on the outside of the box-one on each lid, and one off the bamd of the cylinder. It will be seen that the letters is the illustration spell CAT. Now if the discs D and E have been set so that their slots will pass F F and the prongs through them when this word is put together, the top lid can be removed. A slot to admit the coin can he made in the top lid. Any other word can be used.-" Hobbies," London.