Indeed, it is not easy to be accurate in an account of anything, however simple. Zoologists often disagree in their descriptions of the curve of a shell, or the plumage of a bird, though they may lay their specimen on the table, and examine it at their leisure; how much greater becomes the likelihood of error in the description of things which must be in many parts observed from a distance, or under unfavorable circumstances of light and shade; and of which many of the distinctive features have been worn away by time. I believe few people have any idea of the cost of truth in these things; of the expenditure of time necessary to make sure of the simplest facts, and of the strange way in which separate observations will sometimes falsify each other, incapable of reconcilement, owing to some imperceptible inadvertency. I am ashamed of the number of times in which I have had to say, in the following pages, "I am not sure," and I claim for them no authority, as if they were thoroughly sifted from error, even in what they more confidently state. Only, as far as my time, and strength, and mind served me, I have endeavored down to the smallest matters, to ascertain and speak the truth. Nor was the subject without many and most discouraging difficulties, peculiar to itself. As far as my inquiries have extended, there is not a building in Venice, raised prior to the sixteenth century, which has not sustained essential change in one or more of its most important features. By far the greater number present examples of three or four different styles, it may be successive, it may be accidentally associated; and, in many instances, the restorations or additions have gradually replaced the entire structure of the ancient fabric, of which nothing but the name remains, together with a kind of identity, exhibited in the anomalous association of the modernized portions: the Will of the old building asserted through them all, stubbornly, though vainly, expressive; superseded by codicils, and falsified by misinterpretation; yet animating what would otherwise be a mere group of fantastic masque, as embarrassing to the antiquary, as to the mineralogist, the epigene crystal, formed by materials of one substance modelled on the perished crystals of another. The church of St. Mark's itself, harmonious as its structure may at first sight appear, is an epitome of the changes of Venetian architecture from the tenth to the nineteenth century. Its crypt, and the line of low arches which support the screen, are apparently the earliest portions; the lower stories of the main fabric are of the eleventh and twelfth centuries, with later Gothic interpolations; the pinnacles are of the earliest fully developed Venetian Gothic (fourteenth century); but one of them, that on the projection at the eastern extremity of the Piazzetta de Leoni, is of far finer, and probably earlier workmanship than all the rest. The southern