The Symmetrical Spherical Top

Abstract

THE plastic toy top described by C. M. Braams1 recalls a similar top described in some detail in Prof. John Perry's “Operatives' Lecture of the British Association Meeting at Leeds, September 6, 1890”, or in his book “Spinning Tops”, 67–74 (Society for Promoting Christian Knowledge, 1890). He gives the reason for the unusual behaviour of the top in terms of the rule : “Hurry on the precession and the body rises in opposition to gravity”, and ascribes the theory of the effect to Lord Kelvin (1874). Perry's Fig. 35, which is on p. 75 of “Spinning Tops”, is almost the modern “Tippe Top”.