previous to making the laborious experiment of trying to obtain a copper plate for printing, with lines in relief "one-eighth of an inch in thickness!" when a mere hair line would have sufficed.

Mr. Spencer experienced great difficulty to avoid the brittleness of the copper deposit, and tried plaster of various thicknesses, and solutions differing in strength, in all of which he seems to have displayed considerable perseverance; and, which, besides what he sought, led him to the discovery that by a clean surface the coating of copper became adhesive; and the reverse, if not freed from grease, or oxidation, by employing a solution of nitric acid.

Mr. Spencer's paper is divided into two portions. The first refers to executing engravings, the second to forming moulds and castings of medals, ornaments, &c., and are said to have all been made simultaneously, that is, between Sept., 1837, and May, 1839. Whether any improvements between May and Sept., 1839, are introduced, is not stated; neither do any letters or affidavits accompany the communication. Specimens illustrating the progress of the experiments from first to last were exhibited to the Society 12th Sept., 1839, showing some of the early specimens, of a very brittle and useless character for any purpose in the arts; and here it was that Mr. Spencer received a most valuable hint from Mr. Dancer, whose experiments were not only freely communicated to him, but his very apparatus

obtained from him by Mr. Spencer; yet without the least acknowledgment then, or since, of having acted otherwise than by his own unaided judgment. Yet we see that the first promptings were given at the Liverpool meeting of the British Association, by Dr. G. Bird's simple and very ingenious little galvanic apparatus-that the scientific journals were rife with discussion on applications of galvanism to useful purposes of the arts-that Mr. Jordan, a correspondent of the Mechanics' Magazine, in the plainest and most intelligible terms, explains identically what Mr. Spencer has a little, and but very little elaborated. Lastly, therefore, that, through the Mechanics' Magazine (which Mr. Spencer was regularly taking in), the experimental results obtained by Mr. Dancer, and the reports, in April and May, 1839, in the public papers, of Jacobi's experiments, all bring such broad hints and abundant assistance to aid Mr. Spencer, that he is rather to be praised for his application to the extension of what was already known on a smaller and less perfect scale, than to be adjudged a discoverer, much less "the father of electro-metallurgy," having a "preference to every other claimant." He commences his paper by saying, "I do not profess to have brought forward a perfect invention." He should rather have said, "I do not profess to have brought forward a perfect improvement of what has already been crudely suggested by others."

It is a remarkable fact that Mr. Spencer has made no

useful or profitable application of the electrotype process, of which his first experiments gave promise; neither did he early secure its applications by patent right, patenting only, at an after period, a portion of the process, of little or no benefit to him. The consequence has been that he has been left immeasurably in the background. It does not say much for Mr. Spencer's possession of originality of genius and philosophical acumen, which a perusal of his paper on voltaic electricity would persuade us he considers belongs to him, so long to have remained an absolute cypher in an art entirely new, and capable of modifications and applications yet untried.

The facts now set forth have slumbered near seven years, and are only now given lest they should be entirely lost. I have every possible respect for Mr. Spencer for what he has done; but common candour obliges me to own that I consider that he has only followed in the footsteps of others, repeating their experiments with some little improvement; but certainly neither at the first originating a new art, nor afterwards doing much to add to its resources, or promote its progress.

London, January, 1844.

[To this letter, Mr. C. J. Robertson, the then editor (but since deceased) of the Mechanics' Magazine, appended the following remarks:

"Mr. Dircks has proved beyond all doubt that we have made a great mistake in advocating so strenuously

the claims of Mr. Spencer to the invention of electrography. No one, however, can suppose that we would intentionally exalt any one, at the expense of our own journal, which we are now pleased to find was the honoured medium of the first distinct revelation of this important art to the public, by an old and esteemed correspondent of ours, Mr. Jordan. Whatever Mr. Bessemer, Mr. Dancer, or Mr. Spencer, or others may have previously said or done, it was in private-made no secret of perhaps, but still not communicated to the public at large-not recorded in any printed work for general benefit. For anything previously done by any of them, the art might have still remained in the profoundest obscurity. No published description of an earlier date than Mr. Jordan's can, we believe, be produced; and when we look upon that description, it is really surprising to see with what fulness and precision the writer predicated of the art, nearly all that has been since accomplished. In supporting, as we did, the claims of Mr. Spencer, to be considered as the first discoverer, we had lost all recollection of Mr. Jordan's communication. We had no personal acquaintance with either of the gentlemen, and could have no motive for favouring one more than the other. We took up the cause of Mr. Spencer with spontaneous warmth, because we thought him to be a person most unfairly and ungenerously used; as in truth he was, so far as the intention went, by those who having at the time none of

the reasons we now have, for questioning Mr. Spencer's pretensions, yet obstinately refused to acknowledge them. If it should seem to the reader more than usually surprising that Mr. Jordan's paper escaped the recollection of the Editor, through whose very hands it passed to the public, his surprise will be lessened, perhaps, when he observes, how it appears to have also escaped the notice, or been passed over in silence, by every one else down to the present moment-even of those, not a few, who have expressly occupied themselves with the history of electrography-Mr. Noad, for example, whose very candid and impartial work we reviewed in our last number, and who specifies the Mechanics' Magazine as one of the publications which he consulted in its preparation. To us the most surprising thing of any connected with the case is, that neither Mr. Jordan himself, nor any of his friends, should before now have thought it worth while to vindicate his claims to the promulgation of an art which justly entitles him to take a high place amongst the benefactors of his age and country.— ED. M. M.]