See, the letters that I bring
Change their meaning quite;
Spell a hard and heavy thing,
Spell a soft and light.

[Solution]

No. LI.—A TEST OF GRAVITY

Set a stool, as is shown in the diagram below, about nine or ten inches from the wall.

Clasp it firmly by its two side edges, plant your feet well away from it, and rest your head against the wall. Now lift the stool, and then try, without moving your feet, to recover an upright position.

It will be as impossible as it is to stand on one leg while the foot of that leg rests sideways against a wall or door.

No. LII.—BILLIARD MAGIC

Place a set of billiard balls as is shown in the diagram, the spot ball overhanging a corner pocket, and the red and the plain white in a straight line with it, leaving an eighth of an inch between the balls.