Title:1751 ORIGINAL, SUPERB MANUSCRIPT BOOK OF GEOGRAPHY, ASTRONOMY AND NAVIGATIONAL WISDOM AT THE THEN APEX OF SCHOLARLY KNOWLEDGE DURING THE AGE OF SAIL
Book Condition: Good+
Size: 8vo - over 7¾" - 9¾" tall
Publisher: England  1751
Seller ID: 0002563
On offer is a superb, original ancient manuscript book of English origins, titled "Some Memorandums Relating to Geography and Astronomy... Of the Figure and Extent of the Earth." Dated 1751, even casual reading finds the book filled with what was then cutting edge information being a mere 23 years after Newton's Principia appeared in English. The Age of Sail, Britain's dominance of the waves spurred science in the areas of navigation, astronomy and the mathematics of Geometry all related and discussed herein. Historians and researchers of the era will undoubtedly recall this was written at the time John Harrison the English clockmaker perfected his marine chronometer. Handwritten by 'W.B.' we surmise a professor or other academic or even perhaps someone with the Admiralty or even an active command along with a student or assistant as evidenced by a different hand. Sometimes WB offers a notation of the other's writings. Here are some examples: time calculation based on the known hour of day at another location on the globe: "The hour being given in any place, as at London, to find what hour it is in any other part of the world. Rectify ye globe for London... fix ye index of ye dial plate to the hour given suppose 4 oclock in the afternoon, this being done turn the globe, & bring any places successively to ye Meridien then ye index or hour point will shew ye true hour at ye place required... Rome... Constantinople... Fort St. George in East Indies... Pekin in China... Jamaica... Barbadoes..." "On the Longitude and how to find it... This is call'd the Longitude because the earth was supposed longer East to West, than from North to South... to find the true distance from E. to W. see Gordon's table pa 9... By this longitude here, is not meant that wch is so much sought for and desir'd, the Eastening & Westening of Vessels in their Voyages, call'd by Gordon the Opprobrium Navigatorum pa 15, but only the distance between the given place and the first Meridian inscrib'd on the Surface of the Globe, by Bringing the given Degree of Longitude to the Brazen Meridian and reckoning upon the same meridian... To find the Longitude of any given place, bring it to the East side of the Meridien, and observe what degree of the Equator is cutt by the Meridien, for that is the Longitude of the given place... reckoning upon the same Meridien the degree of Latitude given, make a mark with chalk on the point where the Long. & Lat. meet, for that is the place desired..." "The terrestrial Globe represents the true shape of the Earth (or very near it)... 1st by the Eclipses of the moon... 2ndly by the roundness of all other planetary bodyes, as the Moon, Jupiter, etc. it may be inferred... 3dly the Earth is demonstratively round because many persons keeping constantly from England in a Western Course of sailing have pass'd the Magellan Straits, gone on to the Philippine Islands, coasted down by Cochin China... Cape of Good Hope, keeping still to a Western Longitude till they make the Canary Isles, made their return into the North of England." Other data required for navigators, explorers, horologists, clock-makers, cartographers, geographers, meteorologists and other academics of the time would all have interest in the exercises, examples and adding further depth are a number of illustrations hand drawn making for an instructional guide of geographical and celestial problems with solutions. Other subjects include: measurements of the earth, its geographic coordinate system, the significance of the earth's poles and axis, finding longitude or latitude, calculating the placement of the sun in respect to the earth at a certain time, planetary movement, celestial topics such as the rational horizon and the zodiac circle, eclipses, equinoxes and solstices, the oblique descension of the sun, the "brazen meridian," calculation of time including earth's seasons and lunar years, the origin and methodology of the Julian calendar, discerning distances around the world, and some geographical features of earth including equatorial islands. The subject of navigation appears on the first page with proof that the earth is spherical setting the tone for the next 44 pages or so. [We also note that in a few areas are side notes or addendums. For example one area contains Kingdoms of the World: Britain, France, Germany, Persia and Israel just to name a few. Another note shows the capital cities of the great nations and interestingly Jerusalem is specified as the capital of Israel.] 18 x 16 cm. Some age toning and rubbing to the edges, one leaf split at hinge but overall G+.