The cylinder, being keyed upon its axle as it is intended to run, is lifted by a tackle or crane, and lowered so that each of its journals rests upon a stout steel straight-edge placed so that its upper surface is exactly level and parallel with its fellow. These straight-edges should not only be so rigid as to suffer no sensible deflection from the weight of the cylinder, but they should be very hard and smooth, and great care should be taken to keep them free from indentations. The journals of the cylinder must also be round and polished. The cylinder can now be loaded on its lighter side, or vice versa, until it will remain perfectly motionless when stopped in any part of its revolution.