Peter Mark Roget 
Thesaurus of English Words and Phrases [PDF ebook] 
Classified and Arranged So as to Facilitate the Expression of Ideas and Assist in Literary Composition

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. While endeavouring to pay due regard to the author’s disposition of all the words which he had proposed to add to the Thesaurus, or to repeat in its pages, I have thus sought rather to connect than to separate the several parts of the work, and, without obscuring the independence of each by too much blending, to combine them in an entire structure which might adequately represent the complex vocabulary of our language.