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The description and use of ... Gunter's quadrant ... To which is added, the use of Nepiar's [sic] bones in multiplication, division, and extraction of roots ... / [William Leybourn].

  • William Leybourn
Date:
1731-1732
Catalogue details

Licence: Public Domain Mark

Credit: The description and use of ... Gunter's quadrant ... To which is added, the use of Nepiar's [sic] bones in multiplication, division, and extraction of roots ... / [William Leybourn]. Source: Wellcome Collection.

    11/166 page 5
    eRe NC ie Secr. I. Of the Circle of Months. rT His Circle of Months is figured ie with the Letters 7. P.M. A, WE February, March, April, May, &c. each Month being divided unequally, ac- . cording to the Number of the Days that are contain’d therein, as before is pumatcd, : And now to find any Day of the Month throughout the Year: Firft, fearch out the Month, and, from the Beginning thereof, account the fmall Divifions from one Monthto another, each of them for five Days, (unlefs your Qua- drant be large,and the Month divided in- to every Day )and by this Means youea- Day of the Month defired, which will - be much eafier by Practice, than can be exprefs’d by Words: And here note, — that every roth Day 1s diftinguifh’d by a longer Line then the refit, thus, if Center) to the roth Day of Fanuary, — A
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