CHRISTMAS is the great season for amateur theatricals, and in hundreds of village halls and local Assembly Rooms-and even in the ships of the Royal Navy, with which tonight's talk will primarily deal-dress rehearsals arc going on, stage managers are desperately improvising last-minute effects, leading actors are contracting influenza, and producers are con. tracting sore throats. But no amateur show was ever known to flop, because even if the audience do not enjoy it, the actors ultimately do.