Projectors, pranks and perpetual motion

Projectors, pranks and perpetual motion

From the satirical to the serious, the quest for longitude provoked a wealth of responses, some more worthy of attention than others.

The passing of the 1714 Act of Longitude and the potential award of £20,000 from the British government attracted as much derision as it did serious attempts to solve the vexing problem.

Mocking the Powder of Sympathy

The quest for longitude was already the butt of jokes by the seventeenth century. In 1688, a satirical pamphlet proposed that a wounded dog be placed on each ship. The knife that made the wound or a bandage that had bound it would remain at the home port before being plunged into the ‘Powder of Sympathy’ at midday. This would cause pain in the dog’s wound thousands of miles away, causing it to howl and thus providing a ‘canine time signal’ from which the longitude could be determined on the ship. The pamphlet said that Sir Kenelm Digby had investigated the powder, but was mocking it alongside other ideas.

Whiston and Ditton's rockets

William Whiston and Humphry Ditton proposed that vessels moored at known locations could fire rockets vertically to 6440 feet at set times. Navigators would look for the explosion and gauge their bearing and distance from the moored vessel by compass and by timing the difference between the flash and sound of the rocket exploding, or by measuring its elevation. Whiston and Ditton thought the explosions might be visible for a hundred miles. Despite the obvious drawbacks of the scheme, it was instrumental in the passing of the Longitude Act, although Whiston’s controversial character meant that it soon became the subject of ridicule.

Jeremy Thacker, The Longitudes Examin’d

Some intriguing schemes emerged in the wake of the Longitude Act. In November 1714, advertisements appeared for Jeremy Thacker’s The Longitudes Examin’d, which described a clock sealed in a vacuum to protect it from external influences. The pamphlet seemed to be very knowledgeable about clocks and is notable for using the word ‘chronometer’ for a marine timekeeper. But it reads like a satire: the ‘pretty machine’ would ‘I am (almost) sure … do for the Longitude’, and he confessed that, ‘If it be ask’d why I wrote the Book at all, I’ll frankly answer, That I wanted Money’. And above all, it made fun of many schemes being put forward by others.

Bedlam

As it had in the 1600s, solving the longitude problem was linked with a range of seemingly impossible tasks, such as constructing a perpetual motion machine. Anyone associated with these schemes was likely to be, or to become, mad, it was thought.  Published in 1735, the final scene of Hogarth’s The Rake’s Progress shows the interior of Bethlehem Hospital, the lunatic asylum also known as ‘Bedlam’. One of the inmates is drawing longitude schemes, including Whiston and Ditton’s rockets, on the wall. The implication is clear: only madmen attempt to solve the impossible.

Jane Squire, 1743, A Proposal To Determine Our Longitude

This is the only known idea to be published by a woman under her own name. Squire’s scheme involved dividing the heavens into 1440 geometric ‘Cloves of Longitude', bisected by 720 parallel ‘Rings of Latitude'. This produced over one million segments called ‘cards', each centred on a constellation. This, in theory, would allow sailors to take a precise reading as they navigated and to use an astral clock to correct the difference between apparent and mean solar time. Once the meridian was reset to Bethlehem, ships that stayed true to their course could be piloted by matching the skies to special star cards. Despite some correspondence with the Board of Longitude, Squire died without reward.

Irascible inventors

By the nineteenth century, the Board of Longitude was receiving a huge range of ideas for different ways of finding longitude (and other ideas). Henry Constantine Jennings, a chemist and inventor who, among other things, campaigned against the waste of stationery in the House of Commons, suggested several devices, including a mercury-filled log glass for measuring speed and an ‘Insulating Compass’. This, he said, always pointed due north, allowing mariners to determine latitude and longitude. Sadly, his often insulting letters won him no friends and his ideas were later discredited.

Wild ravings and gospel truths

The Board of Longitude also received many ideas that even they found perplexing. In 1822, a longitude scheme devised by George Wedel, of Holstein, and addressed to the House of Commons, was referred to the Board. Wedel claimed he could determine longitude by proving that the earth is motionless. The Board thought the scheme ‘wholly unimportant, and not entitled to encouragement from any department of the British Government’. In 1828, John Horner sent a long manuscript filled with diagrams explaining the workings of nature, including gravity, physical attraction, perpetual motion and longitude. This ‘Gospel System’ was, he said, a gift from God to humanity. The Board decided to ignore him.

The never-ending quest

Although the Board of Longitude received many ideas it chose to ignore, there were many it took seriously. These included schemes that might solve the problem of observing Jupiter’s satellites from a moving ship as a way of finding longitude. Many of the proposals sent to the Board were for devices that would keep a telescope steady as the observer looked at Jupiter and its satellites as the ship rocked back and forth. In 1824, for instance, the Board seriously considered Samuel Parlour’s shoulder-mounted apparatus for this purpose, even arranging sea trials. Sadly, it proved unsteady in strong winds.