Physics, Electricity & Magnetism, Energy & Motion, Optics & Light, Maths & Measurement

Our wooden-boxed brass sundial is a completely self-contained portable instrument, inspired by a design from the 18th century instrument maker Peter Dollond, founder of a great optical empire. The original is in the London Science Museum. Instruments like this were once used by explorers and navigators to tell the time anywhere in the world. For this to be possible, the gnomon, which casts the shadow, can be set for latitude on a sliding scale and the whole instrument oriented for direction by means of a magnetic compass in the base. Height adjustable legs ensure that the instrument is used upright. Box measures 4" square, 2.5" tall.

From first scientific toys that used animated images to modern movies, retinal persistence has been fundamental to fooling the mind into believing that a series of static images are in motion.

In1834, the English mathematician George Horner proposed a practical apparatus based on the phenakistoscope of Plateau and Stampfer (1830). It eliminated the need for a mirror and it enabled several people at the same time to view the moving pictures- an advance over the single spectator of the earlier toy.

Includes 14 animated strips.

Blending specially formulated inert gases, it creates a -- dramatic display of light inside a hand-blown glass sphere! -- Fascinating to watch, this light is even more fun to play with! Just place your fingers on the glass surface and watch as colored bolts of glowing light follow your every move. You can actually "feel" the energy as the light gently tickles your fingertips! -- Featuring a super-large 8" glass sphere, the 360 Plasma Ball can be viewed from any angle, and comes complete with its own AC power adapter and unique designer base that compliments any room. AC powered adapter included. -- Simply the BEST Plasma Ball on the market today!