Practical plane and solid geometry for advanced students, including graphic statics, adapted to the requirements of the South Kensington syllabus (1899)
Harrison, Joseph, Baxandall, George Albert · London Macmillan · leaf 144
/e vibration. The circle in which Amoves is called thedirecting circle, and P v~> the directing point. The amplitude of the vibration is equal to CA or CP;that is, to half the travel of the vibrating point M, or tothe radius of the directing circle. The period of the vibration is the time which… … fraction of the period which has elapsed since the movingpoint last passed through its middle position in the positivedirection. Thus in the figure let from A to B be thepositive direction, and let the rotation of CP be clockwise,as indicated. Then the phase for the position of J/shown inthe figure…
