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THE POPULAR SCIENCE MONTHLY. 



seen in them little except evidences of " ig- 

 norance," " incompetency," " confusion," 

 " inconsistency," " perverted terminology," 

 " fanciful discriminations," and, massing 

 together these faults, he winds up his arti- 

 cle with the inference of Spencer's " incom- 

 petency 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 unac- 

 quainted 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 in- 

 timated, and certainly not so grossly igno- 

 rant 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 discrimi- 

 nation to separate them ; and if a question 

 could arise as to which is meant, the charac- 

 ter of the discussion would sufficiently deter- 

 mine it. Mr. Wright was no more justified 

 in assuming that, by " Descriptive Geome- 

 try," as he was dealing with it, Mr. Spencer 

 meant " certain methods of geometric con- 

 struction, 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," em- 

 ployed, as it was, in its scientific signifi- 

 cance, Mr. Spencer did not mean Monge's 

 " Geometrie Descriptive " of a hundred years 

 ago, in which theorems and their applica- 

 tions to drawing were mingled together, but 

 he meant the branch of mathematical sci- 

 ence which has since grown up under this 

 title, while omitting all mention of the prac- 

 tice that gave it the name of Descriptive Ge- 

 ometry, 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. 



EDITOR'S TABLE. 



INTERNA TIONAL COP YRIGET. 



DR. C. E. APPLETON", of London, 

 has an article in the February 

 Fortnightly on " American Efforts af- 

 ter 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. II. 



