The plate will consequently turn on this axis as on a hinge.

At the top of the plate, _d_, a small projection of the tin turns inward, and to this one end of the cord, _m m_, is attached.

This cord passes back from _d_ to a small pulley at the upper part of the board, and at the lower end of it a tassel, loaded so as to be an exact counterpoise to the card, is attached.

By raising the tassel, the plate will of course fall over forward till it is stopped by the part _b_ striking the board, when it will be in a horizontal position.

On the other hand, by pulling down the tassel, the plate will be raised and drawn upward against the board, so as to present its convex surface, with the words STUDY HOURS upon it, distinctly to the school.