This is a very old and ingenious puzzle and an amusing toy. It is very simply made. A number of blocks of wood must be cut, 4"x 2 1/2" x 3/8". Any number may be used, but not less than seven - twelve for the most traditional type.
Round the edges of the blocks and make them smooth with sand-paper, as in Fig 488. if the toy is to be given to a toddler. Cut strips of tape about 1/4" wide and long enough to go over the rounded ends of the blocks, a, b b, etc., in Fig. 488. There are three tapes to each block. Nail and glue tape a to the center of upper end of block A; it is then brought over and downward under the middle of the lower end of block B and fastened.
Tapes b b are now fastened to the opposite end of A about 1/4" from the end on either side, and are then brought round the opposite end of B, as shown in the diagram. The center tape c is fastened to B and then brought down underneath to the center of the opposite end of C. The tapes must be arranged like this throughout the whole set of blocks.
Fig. 489. shows how the blocks are held when they are all complete. Top block A must be turned so as to bring the second block to the same level. The top of this block then falls, and it appears to pass rapidly down first on one side and then on the other, until it reaches the bottom. This is only what seems to happen. What really happens is that the second block becomes reversed and falls back again, in its former position. This makes it come level with the third block, which at once falls over on the fourth, and so on to the end of the ladder. A very illusive effect is thus produced. The blocks might be colored with some bright enamel paint, contrasting colors on opposite sides.
Jacob's Ladder Toys from Victorian Era
