Stonehenge 56 Year Cycle

Abstract

Colton and Martin¹ are to be congratulated on the independent discovery of eclipse cycles based on a fixed number of lunations. The cycles that they list are among the long list of cycles which have been exhaustively studied and described in a rare book by Professor G. van den Bergh² that is seldom found outside astronomical libraries. The particular cycles tabulated by Colton and Martin are named, in order of increasing length, Hepton, Octon, Inex, etc.