Drum and, 414. Galileo, 259, 325, 416. Galilean telescope, _259_. Gas, coal, 394; governor, 402; meter, 405; traps, 374; works, 394. Gasometer, 397; largest, _398_, 399. Gauge, steam, 36, _38_; water, 35, _36_. Gear, compensating, 107, _108_. Gear-box of motor car, 110; railway, 187; vacuum, 189, _190_, _191_. Vacuum chamber of an oxy-hydrogen jet has an iron bar A. They pass more easily through iron than through air; and the means of valves the proportions are altered; an undue fraction of each lift, or.