Longitude by Dava Sobel is a book about how the first accurate clock for determining longitude was made. The book starts off by describing the longitude problem which is about how difficult it is to determine longitude at sea. In order to determine longitude, two clocks are needed, one from the home port and one based upon the local time of the ship. The difference in times allows for the longitude of the ship to be determined. However, it is very hard to make accurate clocks at sea due to the swinging motion of ships making pendulums invalid. This was such a problem that multiple governments offered prizes to solve this longitude problem with the British prize being offered by a Board of Longitude when the Board has determined that the problem
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One reason that it is well written is that it leads the reader along very nicely to certain conclusions and assumptions. For example the beginning of the third chapter begins with “Perhaps there was a way to read longitude in the relative positions of celestial bodies” (Sobel 21). After this, the reader is then led through the history of determining longitude with astronomy and the positions of Jupiter’s moons that led to longitude being able to be determined on land. Then, the chapter concludes by showing this in principle in action with the “warrant establishing the Observatory at Greenwich” (Sobel 31). This style of leading the reader on and explaining and offering background on everything makes it well written in my eyes. Another reason I consider it well written is that it directly connects to the sailors and shows the effect of these new devices on the navigation. This is shown with the description of how a sextant should be used: “many of the careful navigators sat… and the real stickers lay down flat on their backs”(Sobel 91). It shows that navigation was a very tedious process due to the uncomfortable circumstances. The effects of the accurate clock on mapmaking is also shown by James Cook being able to make “the first-and highly accurate- charts of the South Sea Islands”(Sobel 150). Showing how beneficial the development of the marine chronometer was for
One reason that it is well written is that it leads the reader along very nicely to certain conclusions and assumptions. For example the beginning of the third chapter begins with “Perhaps there was a way to read longitude in the relative positions of celestial bodies” (Sobel 21). After this, the reader is then led through the history of determining longitude with astronomy and the positions of Jupiter’s moons that led to longitude being able to be determined on land. Then, the chapter concludes by showing this in principle in action with the “warrant establishing the Observatory at Greenwich” (Sobel 31). This style of leading the reader on and explaining and offering background on everything makes it well written in my eyes. Another reason I consider it well written is that it directly connects to the sailors and shows the effect of these new devices on the navigation. This is shown with the description of how a sextant should be used: “many of the careful navigators sat… and the real stickers lay down flat on their backs”(Sobel 91). It shows that navigation was a very tedious process due to the uncomfortable circumstances. The effects of the accurate clock on mapmaking is also shown by James Cook being able to make “the first-and highly accurate- charts of the South Sea Islands”(Sobel 150). Showing how beneficial the development of the marine chronometer was for