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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    Trigonometric. 3 of 22 dee, 37’, the fine thereof isin the firt column, therefore I look for the fecants in the lat, where I finde ©347520, to which adding 10,00C0000 or 10, it is 10, 0347520, the fecant of 22 deg, 37%, 5 Of the Charatter of Logarithmes. The Chara&ter or Chara@erical note of every Looarithme in thefe tables, is the fir(t figure ‘or figures towards the left hand, diftineuifh- ed from the reftby a Gomma: and it fheweth of how many places above’ the place of unites, the abfolute number to that logarithme bes longing doth conf, And thus the character of the Jogarithmes of every numoer leffe than ro is o, but the character of the logarithme of 10 is x, and fo of all other. numbers to 100+ but the character of the logari-hme of 1¢0.is 2, and {oof the reft to tooo, and thecha= racter of the logarithme of 1600 is 3, and fo of the ret to 10000 ; and fo forward, Wherefore, by the character of a logarithme you may know of how many places the abfolute number an{wering to that lo= garithme doth confitt. 6. Lo find readily the complement arithmetical of alogarit hme, The complement arithmetical of a ldgarithme (as itis moft ufually taken) is the refidue of that logarithmie unto 10,000000, As the complement arithmetical of 7, 1079054 1s that which makes ir Up 10, Cocceeo: if therefore 7, 1079054 be fubftraéted froma 10,0000000 the remainer is his complement arithmetical, But to {ubltra& it rea dily,I begin(contrary to the ordinary courfe) with the firft feure toward'the left hand, and-write the complement or refidue thereof unto 9, “and fo I do with the refi, till Ieome tothe Jaft fioure towards the right hand, andchereof I fet down the re(- due unco 10. Thus for the complement arithmetical. of 7, 1079054 I write, for 7 his refidue unto 9 which is°2 3 for 1,8 ; for 0,9; for 7,23 for 9,0; foro, 9; for 5,45and for 4,6: and fo] have this number 218920946, which is the complement arithmetical of 7) 1979054 unto 10, C000000, So if Idefire the complement arithmetical ‘of 99652480, unto 20, 0000000 : J write for 9,0: for 9 again o; for 6, 33 for 5,4 3 for 2,7: for4)53 for §,2'; andthe cypher ; and fo I have ©, 03475205 and before all putting an unite it is 10, 0347520, the complement arithmetical required. The complements arithmetical of the artificial fines are exprefled LDS se (isin nae SEmE Ee a a