Mr. T. S. Davies on Geometry and Geometers. 517 



" With my best wishes for your prosperity every way, I am, Dear 

 Sir, 



" Your much obliged and most humble Servant, 



" Rob: Simson. 

 " I do not dedicate the book to Earl Stanhope for a reason you 

 will know afterwards." 



. Cowley's book is but little known ; and though it is probable 

 that Dr. Simson would be somewhat surprised at its appear- 

 ance, and disappointed with its contents, it is a production of 

 some value to the student of the Geometry of three dimensions. 

 Its value is simply this: that it contains a series of well-de- 

 signed models of planes and solids, such as occur in the earlier 

 parts of the Geometry of Space. The work was constructed 

 for the use of the cadets in the Royal Military Academy (in 

 which Cowley was Professor of Mathematics) ; and I believe 

 the practice of employing such illustrative models has more 

 or less prevailed in this institution ever since. The idea itself 

 was, however, by no means new, and had been used by a 

 writer then so familiarly known as Ward. The method was 

 probably first used in explaining the principles of perspective, 

 and is still much employed by writers on that subject. I am 

 not alone in wishing it were more freely used by modern writers 

 on pure geometry, and especially in geometrical instruction, by 

 our teachers. 



It is stated by Dr. Trail (Life, p. 31), on the authority of 

 some of Simson's letters to Earl Stanhope, that a private act 

 of parliament was contemplated for preventing the importation 

 of any copies (especially of the Latin edition) from abroad, 

 after the example of Buckley's edition of Thuanus. No traces 

 of such an intention exist in these letters, and hence it must 

 have been completely abandoned before he entered upon the 

 printing. There i^, however, abundant proof of Simson's great 

 care and circumspection as a man of business, and the most 

 rigid attention to a compliance with the terms of the statute 

 of Anne, by delivering and registering the nine copies required 

 by that act to be placed in the hands of the Stationers' Com- 

 pany. Nay, so scrupulous was he, that he sent not only nine 

 copies of the work, but nine copies of large paper and nine 

 of the small — as though the size of the paper might consti- 

 tute the larger a different edition from the other ! 



It is altogether unnecessary to give the further letters, or 

 those parts at least which relate to mere business details, — 

 such as the number of copies sent off, speculations as to the 

 mode of disposing of them, and the prices to be charged. A 

 few occasional passages, however, possess interest. 



A great object of Simson's solicitude was the manner of 



