FIG. 1.—JACOB’S LADDER.
FIG. 2.—CONNECTIONS OF JACOB’S LADDER.
The simple toy illustrated in the annexed engraving is very illusive in action. When the upper block is grasped by the edges, as shown in [Fig. 1], and turned so as to lift the second block in the series to the same height, the upper end of the second block falls into an inverted position, and appears to pass downward on the other members of the series, first upon one side of the ladder and then upon the other, until it reaches the bottom. This effect is only apparent, as the second block in reality only falls back to its original position in the series, but in the operation it becomes reversed; what was before the lower end becoming the upper end, the front having exchanged places with the back. This change of position of the second member brings it parallel with the third block, which is then released, and the third member drops over on the fourth, when the fifth block is released, and so on throughout the entire series.
In [Fig. 2] are shown the three upper blocks of the series, 1, 2, and 3, and their connecting tapes, the blocks being represented as transparent and separated from each other a short distance to show the arrangement of the connections. Block 1 has attached to it three tapes, a, b, b. The tape, a, is attached to the face of the block at the center, at the upper end, and extends over the rounded end of this block and under the rounded end of block 2. The tapes, b, b, are attached to the face of block 1, extending downward, under the lower end of this block, and upward, over the upper end of block 2. The tape, a, which is attached to the center of the upper face of block 2, extends over the end of this block, downward underneath the block, and over the upper end of block 3, where it is secured. This arrangement of tapes is observed throughout the entire series.
In [Fig. 2], block 2 is represented as falling away from block 1. When block 2 reaches block 3, the tape, a, will be parallel with the face of block 3, and the latter will be free to fall in a right-handed direction, in the same manner as block 2 is falling in a left-handed direction. When block 3 is parallel with block 4, the fourth block will fall over in the left-handed direction.
The blocks, which are of pine, are each of 35⁄8 inches long, 23⁄8 inches wide, and 1⁄4 inch thick. The tapes, which are each 43⁄4 inches long and 3⁄16 wide, are fastened at the ends to the blocks by means of glue and by a small tack driven through each end of the tape, as shown.