If in the former volumes I felt diffident of my own powers to do any
justice to my subject, I have yet been encouraged by the sympathy and
approbation of those who nave kindly accepted of what has been done,
and yet more kindly excused deficiencies, errors, and oversights,
which the wide range of subjects rendered almost unavoidable.

With far more of doubt and diffidence, yet not less trust in the
benevolence and candour of my critics, do I present this volume to the
public. I hope it will be distinctly understood, that the general plan
of the work is merely artistic; that it really aims at nothing more
than to render the various subjects intelligible. For this reason
it has been thought advisable to set aside, in a great measure,
individual preferences, and all predilections for particular schools
and particular periods of Art,--to take, in short, the widest possible
range as regards examples,--and then to leave the reader, when thus
guided to the meaning of what he sees, to select, compare, admire,
according to his own discrimination, taste, and requirements. The
great difficulty has been to keep within reasonable limits. Though
the subject has a unity not found in the other volumes, it is
really boundless as regards variety and complexity. I may have been
superficial from mere superabundance of materials; sometimes mistaken
as to facts and dates; the tastes, the feelings, and the faith of my
readers may not always go along with me; but if attention and interest
have been exited--if the sphere of enjoyment in works of Art have been
enlarged and enlightened, I have done all I ever wished--all I ever
hoped, to do.

With regard to a point of infinitely greater importance, I may
be allowed to plead,--that it has been impossible to treat of the