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new Axiom, or rather "Quasi-Axiom"--for it's _self-evident_ character is open to dispute. This Axiom is as follows:-- In any Circle the inscribed equilateral Tetragon (Hexagon in editions 1st and 2nd) is greater than any one of the Segments which lie outside it. Assuming the truth of this Axiom, Mr. Dodgson proves a series of Propositions, which lead up to and enable him to accomplish the feat referred to above. At the end of Book II. he places a proof (so far as finite magnitudes are concerned) of Euclid's Axiom, preceded by and dependent on the Axiom that "If two homogeneous magnitudes be both of them finite, the lesser may be so multiplied by a finite number as to exceed the greater." This Axiom, he says, he believes to be assumed by every writer who has attempted to prove Euclid's 12th Axiom. The proof itself is borrowed, with slight alterations, from Cuthbertson's "Euclidean Geometry." In Appendix I. there is an alternative Axiom which may be substituted for that which introduces Book II., and which will probably commend itself to many minds as being more truly axiomatic. To substitute this, however, involves some additions and alterations, which the author appends. Appendix II. is headed by the somewhat startling question, "Is Euclid's Axiom true?" and though true for finite magnitudes--the sense in which, no doubt, Euclid meant it to be taken--it is shown to be not universally true. In Appendix III. he propounds the question, "How should Parallels be defined?" Appendix IV., which deals with the theory of Parallels as it stands to-day, concludes with the following words:-- I am inclined to believe that if ever Euclid I. 32 is proved without a new Axiom, it will be by some new and ampler definition of the _Right Line_--some definition which shall connote that mysterious property, which it must somehow possess, which causes Euclid I. 32 to be true. Try _that_ track, my gentle reader! It is not much trodden as yet. And may success attend your search! In the Introduction, which, as is frequently the case, ought to be read _last_ in order to be appreciated properly, he relates his experiences with two of those "misguided visionaries," the circle-squarers. One of them had selected 3.2 as the value for "_pi_," and the other proved, to his own satisfaction at least, that it is correctly represented by 3! The Rev. Watson Hagger, to whose kindness, as I have alre
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