A Jacob's Ladder unfolded
Watch toy in action (Ogg Theora format, 1.7 MB) (clip info)

A Jacob's ladder is a folk toy consisting of blocks of wood held together by strings or ribbons. When the ladder is held at one end, blocks appear to cascade down the strings. However, this effect is a visual illusion which is the result of one block after another flipping over.

It is called a "tablita mágica" (magic tablet) in Spanish. Jacob's ladders are still handcrafted by indigenous craftsmen throughout Mexico. It is a form of flexagon.

The earliest known reference for Jacob's Ladder is a 1889 Scientific American article^[1]. Despite urban myths prevalent on the internet, there is no known documentation dating it to King Tut's tomb or ancient Egypt, or to the Pilgrims. It has been theorized that its origin is from a Chinese falling-block toy, called "Chinese blocks"^[2].

The toy is called Jacob's Ladder because its seemingly endless tumbling of blocks is said to resemble a dream of angels continuously ascending and descending a ladder to heaven, as dreamed by the biblical patriarch Jacob (Genesis 28:12).

[edit] Construction

Construction of a Jacob's ladder

Arrangement of interlaced ribbons which allow each block to act as if hinged to the next one at either of its two ends. The same mechanism is used in the 1980s toy Rubik's Magic but with plastic strings run diagonally across squares, with the result that the squares can hinge along either of two adjacent sides.

[edit] References

[edit] External links

• Jacob's Ladder and how to make one