The principal purpose of these notes is to correct certain misunderstandings which I believe to be widely prevalent concerning the character of British Trade Unionism during the quarter of a century which followed the establishment in 1850—1851 of the Amalgamated Society of Engineers. The period covered thus begins with the inauguration of the ‘new model’ type of Amalgamated Society, and extends to the end of the trade boom of the early seventies, stopping just short of the Great Depression which set in about 1875.