George Boole 
Calculus of Finite Differences [PDF ebook] 

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. As such Treatises as the present are in close connexion with the course of Mathematical Study at the University Of Cambridge, there is considerable difficulty in deciding the question how far they should aim at being exhaustive. I have held it best not to insert investigations that involve complicated analysis unless they possess great suggestiveness or are the bases Of important developments of the subject. Under the present system the premium on wide superficial reading is so great that such investigations, if inserted.