By the end of the 19th century, Venice—conquered by Napoleon, handed over to the Austrians, plundered by the departing French troops, ruled by the Hapsburgs, and plundered again by the Austrians when they left in the 1860s—had lost much of its former glory. Nevertheless, Venice continued to fascinate travelers, and in this gracefully written book, Norwich (A History of Venice) attempts to portray the city through the eyes of some of its famous visitors of the period. Except for passages drawn from the writings of these travelers, this approach is not entirely successful, particularly in the chapter on Lord Byron, which is mainly concerned with the poet's love affairs. Similarly, the section on Robert Browning has more to do with his enthusiasm for his son's restoration of one of the palaces on the Grand Canal than with Browning's impressions of the city. On the other hand, in the chapter on John Ruskin, who recorded the decaying city in drawings, watercolors and writings, readers get some telling descriptions, and a sense of Venetian atmosphere and everyday life comes across in Norwich's accounts of the paintings of James McNeill Whistler and John Singer Sargent. Perhaps the most compelling chapter is the one on the eccentric, penniless and misanthropic British novelist Frederick Rolfe (Baron Corvo), who, because he alienated everyone who tried to help him, was homeless during much of the time he lived in Venice. For the most part, the book, though intriguing, reveals more about the lives and personalities of the visitors than about Venice itself. Illus. not seen by PW. (Oct.)