Stephenson:Neal:Quicksilver:3:October 12, 1713, 10:33:52 A.M. (Alan Sinder)
From the Quicksilver Metaweb.
Timestamp
Stephensonia
¿ - How is the first chapter SO precisely timed on Columbus Day 1713?
Accurate Timestamp
Is part of the advanced tech Enoch Root MIGHT HAVE an item that will give him a solution to the Longitude problem. Is this time based upon the Prime Meridian or local East Coast time? On land, Galileo's method of sighting the Jovian Moons had been used as of 1650 in Europe[1].
New England Coast & Boston 1645-1646
Sir Robert Dudley (1573-1649), titular duke of Northumberland and earl of Warwick -- a nobleman exiled from the court of Elizabeth I due to her Star Chamber -- charted Boston around the early 1640s using existing Dutch maps with location names provided by John Smith publishing his knowledge as the magnificent Arcano deli Mare, published in Italian at Florence in 1645:1646 in a three volumes folio. Therefore the longitude was known with a ± of 5° accuracy; However, the timestamp smacks of a higher degree of accuracy than that.
Guillaume Delisle's first works were "The Map of the World" and "The Map of the Continents", both published in 1700. These and the terrestrial maps produced subsequently, which surpassed all similar publications, established the son's fame. In 1702 he became élève, in 1716 adjoint, and in 1718 associé of the Académie des Sciences; and, as the young king's instructor in geography, received the title of First Royal Geographer with a fixed salary, an office which was then created for the first time.
Guillaume Delisle adopted entirely new principles in cartography and set about making a thorough reform in that subject. The map-publishers of the time did not know how to utilize the material supplied mainly by the French astronomers of the latter half of the seventeenth century, and Delisle recognized that the new methods of measuring by scale and of marking the places were very valuable for cartography; with this help he therefore produced a new and more accurate picture of the world.
When his astronomical information fell short he carefully examined and sifted all the books of travel and all the maps he could find, and the products of this reading were dovetailed neatly into the facts which he had already at hand. According to a fixed method he worked up the several continents and countries one by one, France in particular. In disputed points he named his source on the map or wrote additional notes, the majority of which were published in the writings of the Academy. One particular recommendation of his charts is that he employed a fixed scale of measurement for regions closely connected with one another. No less famous than his astronomical corrections are the completeness of his topography and the care displayed in the orthography of the names.
Delisle's Carte d'Amérique, 1722
Longitude
Longitude, denoted λ, describes the location of a place Earth east or west of a north-south line called the prime meridian. Longitude is given in an angular measurement ranging from 0° at the Prime Meridian to plus or minus 180°. Unlike latitude which has the equator as a natural starting position, there is no natural starting position for longitude. Therefore a reference meridian had to be chosen. While British cartographers had long used the Greenwich meridian in London, England, other references were used elsewhere, among others Rome, Copenhagen, Jerusalem, Saint Petersburg, Pisa, Paris and Philadelphia. In 1884, the International Meridian Conference adopted the Greenwich meridian as the universal prime meridian.
Longitude may be determined by calcuating the time difference between the location a person is in and Coordinated Universal Time (UTC). Since there are 24 hours in a day and 360 degrees in a circle, the sun moves 15 degrees per hour (360°/24 hours = 15° per hour). So if the time zone a person is in is three hours ahead of UTC then that person is at 45° longitude (3 hours × 15° per hour = 45°). In order to perform this calculation, however, a person needs to have a chronometer (watch) set to UTC and needs to determine local time by solar observation or astronomical observation.
A line of constant longitude is a meridian, and half of a great circle.
This measurement is important to navigation; the discovery of how to measure it accurately was one of the more important discoveries of the 1700s.
Enoch just escaped a riot in New York -- so when would he have performed these calculations? Would Harvard College have the raw data already prepped for the travelling scientist of the day? That and a Huygen/Hooke watch?