Richards' Steam Indicator, 1862

Richards' steam engine indicator No.11274, 1862, with accessories, in wooden box.

This well-known form of indicator was introduced by Prof. C. B. Richards in 1862, and, except for high-speed engines, was still in use in 1925. The great improvement it contained was the employment of a multiplying arrangement by which the stroke of the indicator piston is reduced, and the great distortion of the diagram, through the inertia of the moving parts of the instrument, is generally avoided. The capacity and convenience of the apparatus was also improved in other respects, and most of the instruments since introduced have followed the methods that Richards invented.