TRACT 20.

LOGARITHMS.

327

10th of March 161 5, he writes, “ that he was wholly takenup and employed about the noble invention of logarithms,lately discovered.” And again, “ Napier lord of Markinstonhath set my head and hands at work with his new and admir-able logarithms: I hope to see him this summer, if it pleaseGod ; for I never saw a book which pleased me better, andmade me more wonder.” Thus we find that Briggs beganvery early to compute logarithms: but these were not of thesame kind with Napier’s, in which the logarithm of the ratioof 10 to 1 was 2.3025851 &c ; for, in Briggs’s first attempt hemade 1 the logarithm of that ratio; and, from the evidencewe have, it appears that he was the first person who formedthe idea of this change in the scale, which he presently andliberally communicated, both to the public in his lectures, andto lord Napier himself, who afterwards said that he also hadthought of the same thing; as appears by the following ex-tract, translated from the preface to Briggs’s “ ArithmeticsLogarithmica“ Wonder not (says he) that these logarithmsare different from those which the excellent baron of Marchi -s/071 published in his Admirable Canon. For when I explainedthe doctrine of them to my auditors at Gresham college inLondon , I remarked that it would be much more convenient,the logarithm of the sine total or radius being 0 (as in theCanon Mirificus), if the logarithm of the 10th part of the saidradius, namely, of 5° 44' 21", were 100000 &c ; and con-cerning this I presently wrote to the author; also, as soon asthe season of the year and my public teaching would permit,I went to Edinburgh , where being kindly received by him, Istaid a whole month. But when w'e began to converse aboutthe alteration of them, he said that he had formerly thoughtof it, and wished it; but that he chose to publish those thatwere already done, till such time as his leisure and healthwould permit him to make others more convenient. And asto the manner of the change, he thought it more expedientthat O should be made the logarithm of 1, and 100000 See thelogarithm of radius; which I could not hut acknowledge wasmuch better. Therefore, rejecting those which I had before