Part 12

Notes and Queries, February 3, 1866.

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One Volume, post 8vo., with 130 wood engravings, price 10s 6d,

PERPETUUM MOBILE;

OR,

HISTORY OF THE SEARCH FOR SELF-MOTIVE POWER DURING THE 17TH, 18TH, AND 19TH CENTURIES,

WITH AN INTRODUCTORY ESSAY.

"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.

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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.

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One Volume, post 8vo., with two portraits, price 4s,

INVENTORS AND INVENTIONS,

IN THREE PARTS.

I. THE PHILOSOPHY OF INVENTION, considered strictly in relation to Ingenious Contrivances tending to facilitate Scientific Operations, to extend Manufacturing Skill, or to originate New Sources of Industry.--II. THE RIGHTS AND WRONGS OF INVENTORS, Legally and Politically Examined.--III. EARLY INVENTORS' INVENTORIES OF SECRET INVENTIONS, employed from the 13th to the 17th Century, in substitution of Letters Patent.

"The author enters fully and effectually into the claims and grievances of the inventor. He discusses the arguments for and against the concession of patent right, and examines very ably leaders in the Times on patent monopoly; very clearly dissipating the sophism of the opponents of patent right; also Sir William Armstrong's evidence regarding 'patent monopoly,' &c., affording an interesting and useful publication from its many excellences."--The Scientific Review, September 2, 1867.

"The second part of the volume discusses the right of inventors to a property in their inventions, and thus raises the question of the patent laws, and the twofold issue, whether it will be better to retain them and reform them, or to sweep them away altogether. We are bound to admit that he treats this topic in a fair spirit, and without any taint of bigotry. Mr. Dircks is a man whose opinions are entitled to a hearing."

The London Review, September 21.

"Mr. Dircks treats the real problem and discusses the comparative merits of the existing system, and the advantages which he, together with many others, hopes would follow on the establishment of some judicial council of inventions. The difficulties of the question are enormous, and no one will think the less of them after having gone through this volume.

"The third part, or the lists of their inventions left by many great and some ingenious persons, is interesting and curious."

The Westminster Review, October.

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