"The literature of this subject [Perpetual Motion] is very extensive, but scattered mainly through Patent Records and ephemeral pamphlets. We would especially refer the curious reader to a recent work by Mr. Dircks, entitled Perpetuum Mobile, to which we have been indebted for historical notices. It is extremely complete and interesting as a history."— Chambers's Encyclopædia, Part 15, 1865.
"A very useful collection on the history of the attempts at perpetual motion, that is, of obtaining the consequences of power without any power to produce them."—Professor De Morgan's Budget of Paradoxes, No. 28.—Athenæum, July 15, 1865.
One Volume, post 8vo., with portrait, price 3s 6d,
CONTRIBUTION TOWARDS A HISTORY OF
ELECTRO-METALLURGY,
ESTABLISHING THE ORIGIN OF THE ART.
"In his Introduction, Mr. Dircks has clearly stated the claims of invention, and fairly discussed the only just grounds that can give claim to priority of invention."—The Mining Journal, February 7, 1863.
"In the collection of chronological and other data for the history of various branches and application of science, Mr. Dircks appears to be indefatigable."—The Electrician, February 27.
"It is a useful and clear digest of evidence, and apparently impartially put together."—The Practical Mechanics' Journal (Glasgow), July.