[1722]. Large centre boss, with rim segments bolted to it.
[1723]. Wheel in halves; the boss is held together by two bolts acting as cotters.
Section 92.—WEIGHING, MEASURING, INDICATING PRESSURES, etc.
[1724]. Weighing by a beam with equal arms. Weights A = package B.
[1725]. Weighing by a beam with unequal arms. Weight A constant; leverage of ditto variable by shifting it along the graduated arm of lever.
[1726]. Graduated measuring vessel.
[1727]. Similar principle applied by compound levers with unequal arms. The table is supported on four points on the arms of levers loosely jointed together in the centre; one lever is extended and coupled by a rod to a graduated lever with sliding weight. Knife edges are used for bearings for all weighing machines by leverage. See [No. 958]. This construction is the basis of most of the ordinary weighing machines in use.
[1728]. Duckham’s patent hydraulic weighing machine. The article to be weighed is suspended from the hook, and exerts a pressure on the ram. The corresponding pressure on the liquid (usually oil or glycerine) is indicated on the pressure gauge, which is graduated to show the weight.
[1729]. Spring balance.