The description and use of an universal and perpetual mathematical instrument ... shewing the most expeditious and exact method of solving all practical questions in arithmetick, trigonometry, navigation, dyalling, astronomy, &c. ... / by Benjamin Scott.

  • Scott, Benjamin, -1755.
Date:
1733
Catalogue details

Licence: Public Domain Mark

Credit: The description and use of an universal and perpetual mathematical instrument ... shewing the most expeditious and exact method of solving all practical questions in arithmetick, trigonometry, navigation, dyalling, astronomy, &c. ... / by Benjamin Scott. Source: Wellcome Collection.

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    [ 66] 15. Defcription and Ufe of the Hifteentbi Circle. This Circle is divided into 52 equal Parts, di-- ftinguifhed by large Dots, every one of which: anfwers to 7 Days in the 14th Circle, and num-- bred round with 1, 2, 3, &c. to 52, which endl at December 30: Its Ufe is to know the Num-- ber of Weeks from the Beginning of the Year, to» any Day inthe Year propos’. As for Example,, I would know how many Weeks it is from $/a-- nuary 1, toFuly 9. Look for Zuly 9 in the 11tha or 14th Circle, to which lay the Hair of the Sec— tor, and it will cut the 15th Circle at 27 Weekss and one Day; now becaufe the Year contains 522 Weeks. and one Day, therefore take away onee Day, and you will have juft 27 Weeks from Fe nuary 1 to Fuly 9 inclufive, and fo of the reff. 46. The Defcription and Ufe of the Sixteenth) ircle. ' ° . i This Circle contains the Days in the Year, andi is number’d round with ro, 20, 30, €c. to 365,, being the Number of Days in the Year, wheree that Reckoning ends at December 31, and an-- fwers to the Days in the 14th Circle: The Ufee of it, is. to. know how many Days it is. betweem any two Number of Days propofed. As for Example, Suppofe I would know hows many Days.itis from Zanuary 1, to Fuly 8. Op x:
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