Pratt's Napoleonic books have a certain verve and pace which carries one along on the crest of his own communicable absorption in his subject. But even so, any reader not fully immersed in Napoleonic lore would find himself beyond his depth. The assumption of complete familiarity with persons, great and small, of the era; their place in history, their interplay and interrelation -- all too often hinted at and away. For the initiate, it must be sheer delight, this graphic study -- third in the series- of the high spot of Napoleon's career, the years during which his genius produced the new constitution, a revised tax set-up, the prefectural system, the Napoleonic Code, the Concordat, the reorganization of the army in the midst of successive wars, the revitalizing of the treasury after the Ouvrard affair -- and closing with the defeat of the Prussian might and the challenge of a vacuum which only his genius could fill. The story is told in direct chronological narrative, with interpolated excerpts giving personal closeups, from diaries, letters, etc. Not easy reading- but sure of a critical reception.