This page has been proofread, but needs to be validated.
PREFACE.
ix

the possession, or power of obtaining, other things than these; but, having, in the studies of his hfe, no clue to the principles of essential value, he was compelled to take public opinion as the ground of his science; and the public, of course, willingly accepted the notion of a science founded on their opinions.

3. I had, on the contrary, a singular advantage, not only in the greater extent of the field of investigation opened to me by my daily pursuits, but in the severity of some lessons I accidentally received in the course of them.

When, in the winter of 1851, I was collecting materials for my work on Venetian architecture, three of the pictures of Tintoret on the roof of the School of St. Roch were hanging down in ragged fragments, mixed with lath and plaster, round the apertures made by the fall of three Austrian heavy shot. The city of Venice was not, it appeared, rich enough to repair the damage that winter; and buckets were set on the floor of the upper room of the school to catch the rain, which not only fell directly through the shot holes, but found its way, owing to the generally pervious state of