The supplementary papers added contain, in briefest form, the aphorisms respecting principles of art-teaching of which the attention I gave to this subject during the continuance of my Professorship at Oxford confirms me in the earnest and contented re-assertion.

John Ruskin,

Brantwood,

April 29th, 1880.


PREFACE
TO THE 1857 EDITION.

The greater part of the following treatise remains in the exact form in which it was read at Manchester; but the more familiar passages of it, which were trusted to extempore delivery, have been written with greater explicitness and fulness than I could give them in speaking; and a considerable number of notes are added, to explain the points which could not be sufficiently considered in the time I had at my disposal in the lecture room.