No. XVII.—ILLUSION OF LENGTH
Here is another method by which an optical illusion of length is very plainly shown:—
Judged by appearances, the line A B in the larger figure is considerably longer than the line A B below it, but tested by measurement they are exactly equal.
THE CARELESS CARPENTER
20. A village carpenter undertook to make a cupboard door. When he began to put it in its place it was too big, so he took it back to his workshop to alter it. Unfortunately he now cut it too little. What could he do? He determined to cut it again, and it at once became a good fit. How was this done?
No. XVIII.—PERPENDICULAR LINES
Here is another excellent illustration that seeing is not always believing.