Here is another belated viewpoint. The List server was down when I tried to post this twice on Monday.
John Carmichael wrote: > > > 2. To determine longitude at sea, Harrison's clock was carried on board a > ship traveling west. The clock was set before the journey to show apparent > solar time in Greenwich. The difference between local solar time on the > ship and the time on the clock was used to determine longitude. > > To determine local solar time on the ship, Harrison used a sextant to look > at the sun. How can a sextant, by itself, indicate the time? To determine > high noon, wouldn't he only need a compass to know when the sun "souths" at > high noon? > > As a past navigator, I was very upset with the two scenes I happened to see of what was supposed to be an "observation" to determine longitude. There was no marking of time at the moment of observation except, in the one scene, long afterward, and only a single observation was supposedly used. As Andrew James pointed out, and as I understand it, a sextant can be used to determine "culmination", or the highest altitude of the sun as an indication of local noon. For this, at least two observations are needed. If we also note that these observers did not appear to be even looking at the sun, one wonders what expert help the director had? I will have to look at the program again today. Here is a question for those familiar with 18th century English life. Another thing that bothered me was the almost constant wearing of powdered wigs. Is it true that a naval officer would wear such things AT SEA? Was not the uniform sufficient to establish one's station? A TV reviewer, Howard Rosenberg, wrote a review in the L A Times on July 8. As he pointed out, Sobel devoted less than three pages to the 20th century figure, Rupert Gould. He found that the constant interjection of this very detracting. I did also, but I understand that the screenplay needs some vehicle to carry the commentary that Sobel placed in her text. However, the details of his life seemed unnecessary. You can find Rosenberg's review at http://www.calendarlive.com/tvent/20000707/t000064126.html. or search the archives of the LA Times at www.latimes.com. Claude Hartman 35N 120W (quite removed in time and location from this history)
