Page:Popular Science Monthly Volume 10.djvu/766

746 seen in them little except evidences of "ignorance," "incompetency," "confusion," "inconsistency," "perverted terminology," "fanciful discriminations," and, massing together these faults, he winds up his article with the inference of Spencer's "incompetency for the further development of his encyclopedic abstractions." This looks very much to us like "picking flaws," under the inspiration of a not very creditable purpose. As to the special case there can be no doubt that Mr. Wright made a charge of ignorance against Mr. Spencer, founded on misrepresentation. He says that in his mathematical classification Spencer "has given a prominence to descriptive geometry which might be regarded as arising from the partiality of the civil engineer for a branch of his own art, were it not that he says, 'I was ignorant of the existence of this, as a separate division of mathematics, until it was described to me by Mr. Hirst.'" The insinuation is that Spencer, though educated as a civil engineer, was unacquainted with the branch of mathematical art that is especially familiar to engineers. That this imputation was groundless may be proved by referring to the Civil Engineer and Architects' Journal for 1839-40, where will be found conclusive evidence of Mr. Spencer's early and thorough familiarity with the subject. Among other original papers in the field of descriptive geometry there published will be found a beautiful original theorem which dates back to the time when Spencer was but seventeen. He was not, then, so ignorant as Mr. Wright intimated, and certainly not so grossly ignorant as to confound a practical art with an abstract science, as erroneously represented by his critic. Although the arts grow into the sciences, so that both often pass under the same name, it requires no great discrimination to separate them; and if a question could arise as to which is meant, the character of the discussion would sufficiently determine it. Mr. Wright was no more justified in assuming that, by "Descriptive Geometry," as he was dealing with it, Mr. Spencer meant "certain methods of geometric construction, useful in engineering," than that by "geometry" he meant the art of earth-measuring instead of the science, or by "chemistry" the art of manufacturing paints and dyes, instead of its scientific principles. By the term "descriptive geometry," employed, as it was, in its scientific significance, Mr. Spencer did not mean Monge's "Géometrie Descriptive" of a hundred years ago, in which theorems and their applications to drawing were mingled together, but he meant the branch of mathematical science which has since grown up under this title, while omitting all mention of the practice that gave it the name of Descriptive Geometry, and for which the title Geometry of Position is now substituted. As Mr. Wright suggests the alternative that Mr. Spencer may have meant something else than what he imputed to him as the basis of a charge of ignorance, it is fair to infer that he did not know what he meant; and if he had not been animated by a predisposition to make out a bad case, he would have abstained from taking up the point, or would have dealt with it in a different spirit. We desire to do no injustice to the memory of Mr. Wright, but, as his works are now brought forward in a collective and permanent form, they are the proper objects of criticism, and we have commented upon one part of them, solely in what we consider the interest of truth.



R. C. E. APPLETON, of London, has an article in the February Fortnightly on "American Efforts after International Copyright," which gives a generally correct account of, what has been done here within the last few years to promote that object, but which places us in a false position, which we do not care to occupy. The interest of the topic is such that a few remarks of correction and reminiscence are here proper.

There was a revival of interest in the subject in 1871, which began in an English discussion, when Mr. W. H.