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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    And —, . * dein’ Tk thee oe Latitude 51.3 2.whole com.is G 7.38 28-3.19 14 tC 10045 73 123. Suns dechin. 1§ 10 whofe com,is FH 74 50%. 37:25 | the fummie of half the fides | 6611 t 10.3551676: the difference of half the fides. 08 39.¢ 9:1822106 gives the half the aleernare bafe ZH] 44396 9-99469°5 To whichadding half the true bafe, 3G H 1914 the fumme isthe bafe BH 63 53 | Thus in the-right angled: Triangle BH F, having the bafe. BH 63d. 53%, and hypothenufal FH, being before at firft given 74 d. 50';, we may find the angle at t, faying, : soH-+- Rad =¢BH-becFH, thatis,r BH63 53 10.3095777 : tePH 74 50° 9.43 30804 se H5626 9.7426581 56 deg. 26, which converted into time is 3-ho, 45 44”, before. oF after noon.. | In like fort you may find the hour of night by any known ftar, for the fame things.being given, namely, the latitude of the place, the al- before; and'fo the true hour. and minute (af it were the fur) which note. Then from that ftars right afcenfion fubltraét the.funs right afcenfion, arid the remainer converted into.time, add to the hour and minute before noted,that total. is the true hour:and minute of the night. But in gathering ‘the funs right afcenfion, you muft- remember that it differs every day about one degree or four minutes of time(as more exactly in the Table appears) and {o you mult. allow proporuonably,. for the time that the fun is. paft the ‘meridian of the place for, which your Tables wete made’s.as if it be fix hours paft it, the right afcen= fion is increafed. by about one minute of time; if twelve hours, then tame, & 6. CHA P..