Briggs, Henry (1561-1630); Henri Gellibrand (1597-1636). Trigonometria Britannica: sive De doctrina triangvlorum libri duo, : quorum prior continet Constructionem Canonis Sinuum Tangentium & Secantium, una cum logarithmis Sinuum & Tangentium ad Gradus & Graduum Centesimas & ad Minuta & Secunda Centesimis respondentia ... / a Henrico Briggio ... compositus : posterior verò usum sive Applicationem Canonis in Resolutione Triangulorum tam Planorum quam Sphaericorum e Geometricis fundamentis petità ... exhibet ab Henr. Gellibrand ... constructus.The Origin of Cyberspace no 2.:" Briggs received his M.A. from Cambridge University in 1585, and served as an examinator and lecturer in mathematics there before becoming the first professor of geometry at London's newly founded Gresham College. He spent many years working on problems of navigation and astronomy, but by 1615 had turned his attention entirely to logarithms, which he learned of through the publication of Napier's ' Mirifici logarithmorum canonis descriptio. ( 1614 ) '. While visiting Napier in Scotland during the summer of 1615 and 1616, Briggs discussed with Napier the prospect of changing the latter's original hyperblolic system, in which log -7 = 0. to the system currently in use, in which log 1 = 0 and log 10 = 1. Napier's failing health prevented him from undertaking this task. So the job fell to Briggs, who in 1617 published logarithmorum chilias prima. Containing the first 1000 logarithms of the new canon. This was followed seven years later by his Arithmetica logarithmica, which contained logarithms from 1 to 20,000 and from 90,0000 to 100,000; the remaining 70 chiliads, supplied by Adrian Vlacq, were published in the second edition of 1628. These formed the basis of printed mathematical tables for many years." ( = Norman on the edition London 1624. Dict. of scientific biography II p. 462 -3 :" Vlacq also printed Brigg's tables of logarithmic sines and tangents. The responsibility for seeing this work through the press was entrusted by Briggs, when dying, to his friend Henry Gellibrand, then professor of astronomy at Gresham College, who added a preface explaining the application of logarithms to plane and spherical trigonometry. The work was published in 1633 as Trigonometria Britannica..." EUR 4,500.00
