1 c
Sir
Haveing spent somme time In Calculating the Sun & fixed Stars Hourly Altitude & Azimuth: I have heare in this Small Table shewed the Hourly Altitude & Azimuth of the North Star for Every Hour from yethe Meridian in degrsdegrees & MinMinutes whose declination being suppoased to be in theese our times – : by wchwhich Declination I have Calculated theese tables wchwhich I suppoase may hold good Especially in the Altitude wchwhich is Above Or Below the pole for Every Hour wchwhich is for Every Tenth Latitude from : To the Equinoctiall / And as for the Azimuth I have heare in Like manner shewede it in degdegrees & minminutes Being counted from yethe North / But this way of Azimuth is Calculated without haveing any Respect at All to yethe Altitude and by such a duble way of workeing in such an Eaysey way manner that it may be supposed to be moore dubius but seemeingly very plauseable so ytthat the product of one Simple Multiplycation being Added & Substacted To or from a Nother given sum & Likewise the halfe of the product given wchwhich so done sheweth the Hourly Azimuth for :6: Hours vizd for 10 or 2 before the North Meridian And 10 Or 2 before the South Meridian & Likewise for yethe Hour of 6: And likewise the Rest of the Other Hours in yethe same manner by a doble way of workeing: As suppose ytthat the North Stars Comes to yethe Meridian at yethe Hour of 12: at midnight & I would Have yethe Azimuth at 10 at night and 2 in the Morning and 10 in yethe morning and 2 in the Affter Noon & Likewise 6 in the Morning & :6: at night these Six hours of the North Star Or the Sunn Or Any Other Stars Azimuth is found in the like Manner But for Any Other Hour as suppoase 9 in yethe at night & 3 in yethe Morning & 59 in the Morning and 3 in the Affernoon wchwhich foure hours ar wrought by the product of one simple Multiplication wchwhich is by onley Adding it to Or Substacting it from a Nother Summ given: so ytthat the 24 Hours Azimuth is Resol found by the product of 5 sumsmms of multiplication: by Addition & Substraction: wchwhich maketh mee something to dout of the Exactness theareof: therefore I would desire you if time will permit to Examine the Table for the truth thereof wchwhich if it hold Good; I suppose that there cannot well be a More Eaysey & E way of Callculation of Hourly Azimuth I have in many places Not onely sett doune the degree & minute of the Azimuth but I have likewise pricked by the Minutes Sum Small prickes Every prick being 1 quarter of a minute wchwhich if it be before yethe minminute it is less if after more: for I might as well sett downe yethe serseries as the minutes wchwhich was as dearley shewed in the Calculation but being needless I did omit it: therfore I would desire you to Examine yethe Table & give me Notice of the truth thereof as soone as may be for I shall wery shortley Be for Mary Land: hoping to be at London by the Latter End of this Month or the beginning of the Next SeptSeptember: Haveing no moore at prsentpresent I Remaine at your Command to serve you.
Arthur Storer
Boothby Aug: 10th 1678.
If I should be at London before you wright you may direct your Letter To Mr William Kings Junior Silke weaver in three horshoo Alley in Old Street:
For Mr Isaac Newton of TrinrTrinTrinity CollCollege In Cambridg prs