The great work of Dr. Lewis is his Latin Dictionary, published in 1879, as "Lewis and Short's Revision of Andrew's Freund". This is recognized as the most useful and convenient modern Latin-English Lexicon.
Quite recently Dr. Lewis has brought out a Latin Dictionary for schools, which is not an abridgement of the larger work, but an original work on a definite plan of its own. "It has the prestige", says a critic, "of having been accepted in advance by the Clarendon Press of Oxford, and adopted among their publications in place of a similar lexicon projected and begun by themselves. Thus it may be said to be published in England under the official patronage of the University of Oxford".
Dr. Lewis also published in 1886 "A History of Germany From the Earliest Times".
He ranks among the first Greek scholars of the country, having been for many years a member of the well-known Greek Club of New York, of which the late Rev. Howard Crosby D. D. was pioneer and president.
He also ranks high as a Shakesperian scholar and critic, and as a poet. From his poem of "Telemachus", some lines are transcribed among the poetical selections of this book.
Dr. Lewis has made a profound study of the subject of prison reform and has been, and is, an active worker in that direction, in the New York Prison Association, being on the Executive Board of that Association.
In Stedman and Hutchinson's "Library of American Literature", Dr. Lewis is represented by a paper on the "Influence of Civilization on Duration of Life".