A SIMPLE WATER-MOTOR MOWBUY RITCHIE, TEEUNIVERSITY, EDINBUROH, SCOTLAND The water-motor here described has been found suitable as a means of stirring when the power required is not too large. It can he quickly constructed, and uses in working only a small amount of water. The apparatus consists essentially of two parts. Water under pressure passes through the glass tube A (see Figure I ) , and, emerging from four narrow jets, strikes tangentially the inside surface of the half- @- flask B. A plan of the jet system is given in Figure 2. The half-flask B is free to rotate, and is supported by the glass tube C which passes tightly through the ~ b b e stopper r D, (9 and to which is attached the cork pulley wheel E. This rotating part is supported by an outer glass tube F, held rigidly by a clamp; two metal washers below the pulley-wheel provide the necessary bearing surfaces. The side tube M is employed for the addition of lubricating oil. A convenient diameter of the rotating part B a t its widest part is four to five inches; the jets when in position are about a h o u n ~1 quarter of an inch from the sides. To prevent splashing, the lower part of the apparatus is best surrounded hy some sort of cover. If desired, the stationary entry tube, carrying the water to the jets, may be placed inside the rotating tube carrying the pulley wheel. The water then enters a t the top, and passes downward to the jets. The diameters of the three concentric tubes must, of course, be suitably chosen for the tubes to
I*
provided fit (constructed each other withfrom fairly a suitable larger closely. half-flask) coverSuch and exit has a model, been tube
in use for a considerable time, and has given no trouble. Such a cover is best placed so that the entrance to the exit tube is not directly FIOURE 2 below the jet system; the swirl, imparted to the waste water causes the water to climb up the sides of the cover, and, if not removed, to interfere with the motion of the rotator. For most purposes, some kind of reduction gear must be employed.
Doing easily what others find difficult is talent; doing what is impossible for talent is g e n i u s . - A ~ L 1173
