Credit has been crunched, banks hammered, the economy battered, prices up, hopes down. All classes are being urged to economise, make do and mend, spin things out, avoid waste. It has been ever thus. In times of War, General Strikes as well as Economic Disasters, Governments as well as agony aunts, do-gooders, magazines, books and manufacturers have always exhorted us to tighten the old belts. Hunter Davies looks back at a hundred years of handy, and often hilarious, exhortations as they were applied to Food, Children, Health, Clothing, the Home, Money and Savings. Some of the hints and advice are mystifying, but all are part of social history, and some could prove very useful in today's economic climate. For instance, you really might want to turn some cold scraps of meat into a succulent new dish or knit some old bits of string together in order to make a jolly useful dishcloth…