CYCLING

the use of a bicycle means of locomotion. This pastime undergone many changes since the days of the 19th cent., when the horse,’ a two-wheeled structure pelled by pushing the ground with foot in turn, afforded pleasure young men of the period. Pedals to cranks connected with the back were introduced about 1840. In the pedals were arranged to turn front wheel. Later improvements been steel wire tension spokes ball bearings (1877); Dunlop’s tires (1888); ‘free-wheel’ (1901), brake, changeable gear. The extensively used by the military, during the World War dispatch used the motorcycle. f* CYCLOID, curve traced by a on the periphery of circle rolling plane along a line. When the point is within the circle the curve is termed a prolate, when a curtate c. Both the latter curves known as trochoids.;