art; you will take a large sou, you will cut it in two plates; with what tools? You will have to invent them. That is your business. Then you will hollow out the interior of these plates, taking great care of the outside, and you will make on the edges a thread, so that they can be adjusted one upon the other like a box and its cover. The top and bottom thus screwed together, nothing will be suspected. To the overseers it will be only a sou; to you it will be a box. What will you put in this box? A small bit of steel. A watch-spring, in which you will have cut teeth, and which will form a saw.
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