294 "Mv. J. W. L. Glaisher on some new Facts in 



printed at Gouda in 1626 to Tlacq. In liis preface to the Arith- 

 metica, Ylacq says that somehow (*'^ nescio quo fato ^') Briggs's 

 work came into his hands about two )-ears previously^ and that, 

 perceiving its value and finding it unknown to the mathemati- 

 cians of his country, he thought it would be very useful if he 

 republished it^ reducing the number of decimals given from ]4 

 to 10 and fi-lling in the gap of 70^000. He was deterred, how- 

 ever, by the consideration that Briggs was himself taking steps 

 to accomplish the same object; but having regard to the fact 

 that the latter could not complete the work (to 14 places) for 

 some time on account of the great labour of such a task and his 

 professorial duties, and being uncertain besides whether, when 

 it was published, there might not be some difficulty in procuring 

 copies, which even if obtained would not be very useful unless 

 printed in Latin*^ he, finding he could spare the time, deter- 

 mined to complete the Table so as to give the logarithms of all 

 numbers from unity to 100,000, to ten decimal places. The 

 rest of the preface, which is not lengthy, is devoted to matters 

 not of historical interest. 



It will thus be seen that '\lacq makes not one word of refers 

 ence to Decker^s Telkonst, printed by the same printer two years 

 before; and as on every account some mention was required of 

 this publication, the first work on a new subject ever published 

 in the country, and of the promise contained in the preface to it, 

 ■we are driven to the conclusion that Tlacq must have quarrelled 

 with Decker, or for some other cause have had a set purpose to 

 ignore his book entirely. It will be noticed that Decker through- 

 oat speaks of the contemplated reprint as if it was to be by him- 

 self, assisted only by Vlacq, and that he lays stress on the fact 

 that it will be in Dutch. The Arithmetica (1628), however, was 

 printed in Latin ; and from the remark in his preface, quoted 

 above, it is to be inferred that Tlacq regarded this as the most 

 suitable language. Some light, however, is thrown on the mat- 

 ter by the following circumstances. In 1631, George Miller 

 published at London, under the title ^ Logarithmicall Arith- 

 metike ^ &c. what he asserted was a reprint of ^lacq's Arithmetica 

 of 1628, with an English introduction f^lacq^s preface was 

 omitted, as also his list of errata). The Table, however, was not 

 reprinted at all, the copies being impressions from the same type 

 as that from which the 1628 edition itself was printedf. I have 



* '■' Preeterea etiam rel isto opere ad finem perducto, quod incertus 

 eram, si ejus exemplaria hie eommode aeciperemus, multo minus si in alia 

 lingua ederentur quam Latina^ quorum utilitas non nisi in paucos redun- 

 daret.'"' 



t The reasons for this assertion are given in the paper in the 'Monthly 

 Notices of the Royal Astronomical Society,' cited in the test (p. 295, 2nd 

 line). The same title-page and introduction were prefixed by Miller both to 



