No. XLIII.—FOR CLEVER PENCILS
This diagram, shows how a continuous course is possible without taking pencil from paper, or going twice over any line.
We have purposely left spaces wide enough to make the solution perfectly clear.
No. XLVIII.—A BOTTLED BUTTON
The diagram below shows how the thread within the bottle is severed so that the button falls, without uncorking the bottle or breaking it.
Nothing is needed but a lens to focus the rays of the sun, which pass through the glass without heating it, and burn the thread.