Summary of Dava Sobel's Longitude

Please note: This is a companion version & not the original book. Sample Book Insights: #1 The latitude and longitude lines govern the world today, as they have for centuries. They were first mapped out by Ptolemy in his first world atlas in AD 150. #2 The difference between latitude and longitude is that the zero-degree parallel of latitude is fixed by the laws of nature, while the zero-degree meridian of longitude shifts like the sands of time.
To find your latitude, you only need to know the length of the day or the height of the sun above the horizon, whereas to find your longitude, you need to know what time it is aboard ship and the time at your home port or another place of known longitude. #3 The Age of Exploration was when many sailing vessels set out to conquer or explore new territories, and the wealth of nations floated upon the oceans.
Still, no ship had a reliable means for determining their whereabouts. #4 The search for a solution to the longitude problem was like finding the Fountain of Youth, the secret of perpetual motion, or the formula for transforming lead into gold. The British Parliament, in its famous Longitude Act of 1714, set the highest bounty of all, naming a prize equal to a king's ransom for a practical means of determining longitude.