“When you visit a well-stocked video store these days, it seems the full history of commercial cinema awaits your perusal, either on DVD or VHS. But this plenitude is illusory, a kind of cinematic Potemkin village. Indeed, in the United States, which has churned out the most movies of any nation over the past 100 years, it’s estimated that 50 per cent of the features produced there before 1950 have disappeared, a result of the effects of technological obsolescence, neglect, financial hardship and inadequate archiving. For films produced before 1920, the figure is 80 per cent.”