I have just been wandering around the house with my tape measure trying to find something of similar dimensions to John James Audubon's legendary Birds of America. 'Elephant' is the perfect metaphor, for it is the largest and most spectacular ornithological work ever published. Outlandish, unwieldy, triumphant, it migrated extraordinary distances in search of sustenance and had an inordinately long gestation. Duff Hart-Davis's account covers that critical incubation period hm conception in Louisiana in 1819 to final delivery in London some twenty years later.

'Elephant' is also, more specifically, the name of the size of paper The Birds ofAmerica was printed on. Actually not even quite that - because 'elephant' is 23 X 28 inches and ~udubonw ent one bigger, to 'double elephant': 26 X 40 inches. It is difficult to get an impression