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].

  • Richard Norwood
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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    fiy equalpartsaze from the Equinoctial co every degtee of latithide F namely, of fuch equal partsas a degree of longitude Coriteins 66. ' Wherefore multiplying go deg.bo’, the difference of longitude,by 60, I haye 4200, for the meridional parts conteined in the difference of longitude ; -alfo (by the Jaft probleme) I find'the meridional parts conteined in the. difference of latitude to be ‘1417; fo that, DB. is 1417 parts, and A B 420o-uch parts. ; ok Therefore bythe 4 Cafe of plain Triangles, « .; As the differ. of latitude in parts, D B 1417 parts, co. ar. 6.84863 is in porportion to’Radius : ‘ So isthe differ. of longit. in parts, A B 4200 parts, (3.62325 co the tangent of the Rumb, t D 71 deg, 21’, 10.4738 Which fheweth the courfe from the Summers lands, tothe Li- gzardtobeexea 3deg. 51’ ealterly; or fromthe Lizard to the Same mers Tlands, ve sw, 3 deg. 51° welterly. : Secondly, for the diftancein the Rumb. grees by 60, and to.the product adding the minutes. ) Then by the 2 Cafe of plain Triangles. i As fine complement the Rumb, :s A, 18 deo, 39 covare 0.49514. ‘to the difference of Jatitude:) DB, 1055 miles _ | 3-02325 So.is Radius She Soe 4 to the diftance AD; 3299 miles... 9.53839 Whichis almoft rtoo'leaoues, and this is the diftance meafured in ‘the Rumb ; there isa neerer cut between thefe two places, whereof we fhall {peak hereafterin. Great Circle failing ; but. here, whenfo- Probl. 3. The latieudesof two places, and their diftance givewto fied the Rumb, and dxffcrence of longitudes © py jett ‘upon fome point to the weltward,. 3299 miles’; and then find my felf in the latitude of 32 deg. 254: J.would know upon what point I have made my way good,.and how much] havealtered my longitude’? “miles is 2055 miles,”