Trigonometrie. Or, the doctrine of triangles: divided into two books. The first shewing the mensuration of right lined triangles: the second of spherical ... Both performed by that late and excellent invention of logarithms ... Whereunto is annexed (chiefly for the use of sea-men) a treatise of the application thereof in the three principal kinds of sailing. With exact tables of the suns declination ... and tables of the right ascension and declination of some eminent fixed stars ... Also other necessary tables used in navigation / [Richard Norwood].

  • Norwood, Richard, 1590?-1675.
Date:
1661
Catalogue details

Licence: Public Domain Mark

Credit: Trigonometrie. Or, the doctrine of triangles: divided into two books. The first shewing the mensuration of right lined triangles: the second of spherical ... Both performed by that late and excellent invention of logarithms ... Whereunto is annexed (chiefly for the use of sea-men) a treatise of the application thereof in the three principal kinds of sailing. With exact tables of the suns declination ... and tables of the right ascension and declination of some eminent fixed stars ... Also other necessary tables used in navigation / [Richard Norwood]. Source: Wellcome Collection.

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    , Poliferspt.. vie Some think the Diftance need not be found, nor doth either this orthe former method of Calculation’ require the finding. thereof, rar in itfelf defirable. The angles of Pofition are of good ufe, for they fhew ateach place how far you muft begin. ‘tofhape your firft Courfe from the Meridian, and thofe that will find thefe things, muftealculate for them as we have done, and thefe arethe Difficulties complained of by fome in this manner of Sailing by the atch of a great-Circle, which not- with{tanding practice will teader familiar. I conteffe (as for- merly I have faid) it would be hard to proceed in.all points by the doétrine of Triangles, to calculate every courfe and di- ftance that a fhip muft run, failing by the arch_of a great Cit- cle; which I did duiy confider when I wrote that Treatife, (as my felf-of {undry wayes how thofe difficulties may be fhun- ned, I couldthink upon nane better than by pricking out upon Mercators Ghart, the forefaid longitudes and latitudes by which the forefaid arch.of a great Circle doth paffe; which may well be done within two or three minutes. And fo the arch it felf being pricked or traced out in that Chart, there is no more diffi culty inthe traverfes and reckonings tokeep neet that arch, than there is inthe ordinary ufe-of that Chart.. Which things howto perform on the faid Werearors Chart, I have fhewed in the tenth and la@ probleme of that Subjeé, and thall add no more here, fave onely a blank which fhould have been inferted, in page 158, or 169.3; whereby the things before {pokerof, may be the better underftood ; thisis drawn ina (mall fcale, that it might be conteined ina page :. but in reckonings at fea, the berfome: efpecially it ic be kept on fingle fheets of paper, which may be joyned together, and taken afuader at pleafure. I have yet hopes to do fomething hereafter for the further 1]- luftration of it, and fome other points in the Art of Navigation, if mine-other neceflary occafiotis. will permit ; the rather for that love and courteous enterteinment my former labours have found amongft Sea-men efpecially. But at prefent I fhall add. 14 Feb. 1659+ | Ta.