Sorry Bilgerat, but that's half a pint of rum, not half a litre. The old standard spirit measure was 1/6 gill, so half a pint would be 6 doubles. Taking a double as about a pint, that's 10 pints a day, but of course for men who were both used to it and performing hard physical labour. You couldn't drive a car but I doubt that they would be drunk (which was a serious offence). Also, not all spirits are limited to 40%, for instance my bottle of Bruichladdich is 46% and the Talisker is 45.8%.