The young gentleman and lady's philosophy : in a continued survey of the works of nature and art by way of dialogue . orenoon, I find the Suns Altitude to be 46% and would know the Time of Day, 1 proceed thus : By the Calendar, I fee the Suns Place, on the nth of May^ is a-bout 20° : 30 of « ; and there I ftick the Patch on the Globe,which I bring to the Meridian, and fet the Hour Hand to XILThen I move the Globe and Quadrant fo together, that Icaufe the Patch to touch the 46th Degree on the Quadrant,and then holding both ftill, I obferve the Index points to IX :30, and that was the Hour or Ti
The young gentleman and lady's philosophy : in a continued survey of the works of nature and art by way of dialogue . orenoon, I find the Suns Altitude to be 46% and would know the Time of Day, 1 proceed thus : By the Calendar, I fee the Suns Place, on the nth of May^ is a-bout 20° : 30 of « ; and there I ftick the Patch on the Globe,which I bring to the Meridian, and fet the Hour Hand to XILThen I move the Globe and Quadrant fo together, that Icaufe the Patch to touch the 46th Degree on the Quadrant,and then holding both ftill, I obferve the Index points to IX :30, and that was the Hour or Time when the Altitude wastaken. Euphrof. This feems to be an ufeful Problem ? .Which is next ? Cleon. By the Globe, you may find the Suns Azimuth for any Hour of any given Day of the Year. -^;—Thus, let us take the laft Inftance of May the nth, at Half an Hour afterIX in the Morning; bringing the Suns Place « 20 ; 30 tothe Meridian, and fetting the Index to J^II, I turn the Globetill the Index point to IX : 30, and there hold the Gl,©be; Vol. II. H t^cn 27;^C01TKSE of the Solar JSlaoulEB .7^vvV^ Sl^^SDlSK. and L A D ys Philosophy. 49 the Index points to the Hour of VI, where I hold it faft, andlay the Quadrant over the Patch, and by it I fee the Patch isabout 19 Degrees above the Horizon, which is the Altitude ofthe Sun at Six, for the Morning and Evening of the longeft Day. Alfo, for the fame Day, you find his Altitude -when he is due Eaji or TVeJi, thus : —I bring the Quadrant to the Eaft Point of the Horizon, and turn the Globe till the Patch touches the Edge of the Quadrant, —which you fee is at the 31°, and that is the Suns Altitude when due Eaft or Weft that Day. ^Things reqjiaining as they were, you obferve the Time fhewn by the Index, when the Sun is dueEaft or Weft, wz. VII; 21 in the Morning \ and in the fameManner, you will find it to be IV : 39 in the Afternoon.—And thefe Things you may find for any Day, while the Sun isin the Summer Half of the Ecliptic
Size: 1574px × 1588px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1700, bookdecade1750, booksubjectscience, bookyear1759
