No. LXXIV.
A door, whereof the turning of a key, with the help and motion of the handle, makes the hinges to be of either side, and to open either inward or outward, as one is to enter or to go out, or to open in half.
NOTE.
By making the handle act on a lever communicating with the hinges, they may be raised from their sockets on the required side; and to open in half, it is merely necessary to joint them in the centre.
No. LXXV.
How a tape or riband-weaver may set down a whole discourse, without knowing a letter, or interweaving any thing suspicious of other secret than a new-fashioned riband.
NOTE.
The evident analogy between this Article and No. XXXIII. will be apparent on the slightest view, and in general principle it is similar to Nos. XXXIV. XXXV., &c. It may be performed either by making the stitches of a given length, varying the distance to distinguish the different letters of the alphabet; or, by any arbitrary shape which may be previously agreed upon by the parties corresponding. These arrangements being made, the silk weaver will have nothing more to do, than set his loom to the required pattern.
No. LXXVI.
How to write in the dark, as straight as by day or candle-light.