Transparent acrylic plastic ripple tank, supported in a sturdy plastic frame which has recesses to hold four legs with leveling feet. The tank edges are shaped to minimize undesired reflections. The tank has a drain hole closed by a rubber stopper. With two light alloy uprights to carry a horizontal ripple support rod that is adjustable for height. The ripple assembly, elastically suspended from the support rod, consists of a 4 – 6 V DC motor mounted on a wooden beam. The motor has an eccentric weight which causes the beam to oscillate. Two point sources are provided by two plastic spheres, each mounted on a right-angle rod. A metal rod is fixed centrally into a socket on one short side of the frame to afford support to the illuminant. Overall size of the tank 580 x 500 x 80 mm, window area 370 x 280 mm, the height of tank above bench level (with legs attached) approx. 375 mm. Complete with the following accessories:-