Charles H. Caffin 
How to Study Pictures [PDF ebook] 
By Means of a Series of Comparisons of Paintings and Painters From Cimabue to Monet, With Historical and Biographical Summaries and Appreciations of the Painters’ Motives and Methods

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Lastly, by their works ye shall know them. An artist desires to be known and estimated by his works. Also it may be more useful to study pictures than lives of artists, because an appreciation of one picture leads to that of many. Therefore I have tried to combine with the historical aspects of the subject the matter which is usually treated separately in books of How to study pictures.