[2547]. Spider wheel or tension wheel. Cycle wheels are constructed on this principle, as also were the great wheels at Chicago and Earl’s Court. There are many varieties of this type.

[2548]. Steel railway wheel, with dished web. Wrought iron or steel disc fly-wheels are now in some cases replacing wheels with arms.

Fly-wheels are also constructed with the rim formed of wrought-iron bars wound round and rivetted together, or of heavy wire coiled round and secured with steel belts.


Section 92.—WEIGHING AND MEASURING.

(See also [p. 214].)

[2549]. Differential weighing beam. The lower hook is suspended very near the centre line of the upper one, giving a close adjustment with a short graduated arm.

[2550]. Measuring or feed wheel, for seeds, &c. The little cups dip into the material, and carry it up to a shoot.

Even-flow regulator, for a tap. See [No. 2204A].

[2551]. Wire and sheet V gauge.