The King George III Collection

Natural Philosophy also had its practical applications. As adviser to James Brydges, the Duke of Chandos, Desaguliers was active in various schemes for improving the water supply to London. Some involved the use of early steam engines.

Another important technical challenge was how to find the position of a ship at sea. A ship crossing the Atlantic needed to know how far West it was of London, for example. The inadequacies of existing methods were shown in 1707 when four ships were wrecked in fog off the Scilly Isles, their captains believing them to be in safe waters. Two thousand men drowned. In 1714, the Board of Longitude was set up to offer prizes for practical solutions to the problem. Here was an issue where individuals with a knowledge of natural philosophy had something to offer.
 

One possible solution involved constructing a clock which could keep time accurately on a moving ship. After many years of work, John Harrison achieved this astonishing technical feat and was awarded a prize later in the century. Harrison's chronometer H5 John Harrison developed a series of chronometer, clocks that could keep time very accurately in the conditions found during an ocean voyage. However, it took a long time for him to be awarded a share of the prize money. To press his claims, Harrison had his chronometer, H5, tested at Kew Observatory by George III and Stephen Demainbray in the 1770s. © Science Museum/Science & Society Picture Library