The impact of a travelling theatre show on an unsophisticated audience in the days before television is difficult for a 20th century student to recreate. The average modern child has already experienced a wider range of drama -- plays, puppet shows, animated cartoons and documentary films -- through the medium of television than his great-grandparents saw in their whole lives. To recapture the attitudes and reactions of any 19th century theatre audience requires, then, an effort of the imagination; even more so in the case of popular entertainments, for which there is far less written evidence. It is the aim of this publication to explore, through contemporary pictures and writings, the theatrical experience of that large majority who never went inside a real theatre, and to provide an outline of the development of portable theatres in the 18th and 19th centuries. By the term "portable theatre" I originally intended to indicate only live drama, performed by human actors, in temporary theatres such as tents, booths and "gaffs"; I have, in fact, for reasons which I hope the notes make clear, included material on puppets, peepshows, and even early films. The travelling fairground theatres survived in a limited way into the 20th century before the cinema and then television killed them off. - Introduction.