Astronomy

New instruments
Trust and distrust
New science and new networks
Astronomy and what made the search for Longitude so important

Related link: The New Science - 1550–1800

Today it is easy to take for granted that experiments can be conducted to improve our understanding and knowledge of the natural world around us, but in the first half of the seventeenth century this was not the case.

New instruments

Once natural philosophers gained an appetite for conducting experiments, they designed new instruments to create the different circumstances, or conditions, in which the specimen, animal or mechanical device was to be manipulated and observed. In London, natural philosophers drew upon the skills of a range of makers to have their designs made into a reality. The construction of the air pump, for example, required glass blowers to make the glass vessels into which specimens, animals and mechanical devices were placed; clockmakers to make the intermeshing toothed wheels which operated the air pumps, and furniture makers or turners to make the wooden frames which supported the device.


Air pump: Air pump by Francis Hauksbee, 1708
The Royal Society

This air pump was made by Francis Hauksbee the Elder (1660-1713). He used it in his role as Curator of Experiments at the Royal Society to demonstrate experiments at weekly meetings of the Fellows.

Trust and distrust

While the majority of natural philosophers accepted these activities and the results they generated, because of the quality checks mentioned above, not everyone did. There were examples in the period of people that were not convinced, such as Margaret Cavendish, who was the first woman to visit the Royal Society (the first female Fellow, Kathleen Lonsdale, was not elected until 1945). Cavendish was critical of the Fellows’ reliance on new optical instruments such as the microscope and telescope, suggesting that their eyes were being deceived by the lenses. Her remarks, which were repeated by others, demonstrate that it took several years for new instruments to become trusted by some people. She also wrote many books, one of which was entitled ’The Description of a New World, Called the Blazing-world’, in which she openly satirised the Society and warned of a dystopian future for natural philosophy.

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Cavendish was not alone in her use of satire directed at the Royal Society, and natural philosophers in general. In the late 1670s Thomas Shadwell’s play, ’The Virtuoso’, attracted audiences in London to its story involving the character Sir Nicholas Gimcrack, a natural philosopher who conducts lots of different amusing experiments. Robert Hooke recorded visiting the play in his diary and being outraged that the character seemed to be based on him. Satirical critiques of experiments continued throughout the eighteenth and nineteenth centuries and reveal one view of natural philosophers beyond their own circles. However the monarchy, the government and the majority of the wealthy elite were keen supporters of natural philosophers’ work and could see how new knowledge could be put to use.

New science and new networks

While it is impossible to sum up the many varied ways by which science is carried out today as one single simple method, the concept of the experiment as a way of improving our collective knowledge of the natural world is a crucial part of scientific practice and has its roots in the seventeenth century. Thanks to hubs such as the Royal Society and publications such as ’The Philosophical Transactions’, natural philosophers throughout Europe were part of a network. They may not have always got along on a personal level and they may sometimes have had disagreements, but they realised that the network was essential for getting their ideas accepted by others, as it still is today.

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Astronomy and what made the search for Longitude so important

« From the Stone Age to the Space Age, people have watched and studied the stars. The sky has been our clock, our compass and a source of wonder. We have created a huge variety of instruments to help us study the skies and make sense of what we see [1] ».
Science Museum

A. Literature and Astronomy – one example Jonathan Swift (1667-1745): Gulliver’s Travels [2]

Introduction

This Unit is not aimed at specialists in Astronomy, but to make all readers of Swift aware of the close links between literature and the deep scientific concerns of the 18^th century about Astronomy.

His tale which can be turned into a film for kids is full of one aspect of Swift which is sometimes ignored or at least always downturned: his knowledge and practice of an emerging Science or rather interest of his time, astronomy – illustrated by William Herschel (1738-1822) discoverer of a new planet Uranus whom he knew and worked with. Why was astronomy so vitally important?

« In his novel Voyage to Laputa 1727 Jonathan Swift indicates the existence of 2 satellites of Mars, gives their period of rotation and their distance towards the planet (which are not exact). In 1877 Asaph Hall the astronomer, discovered these satellites and gave them the names of 2 sons of Mars, Arès of the Greek and, Phobos and Deimos mentioned in Song XV of the Iliad.

In Homage to this prediction of Swift, one of the craters of Deimos on Mars’s moon Deimos is named after Jonathan Swift who predicted the existence of the moons of Mars [3] » .

Interesting literary connections

His great-great grandmother Margaret (Godwin) Swift was the sister of Francis Godwin author of The Man in the Moon which influenced parts of Swift’s Gulliver’s travels.

Gulliver’s travels

The volume would have been at least twice as large, if I had not made bold to strike out innumerable passages relating to the winds and tides, as well as to the variations and bearings in the several voyages ; together with the minute descriptions of the management of the ship in storms, in the style of sailors ; likewise the account of the longitude and latitudes ; wherein I have reason to apprehend that Mr. Gulliver may be a little dissatisfied : but I have resolved to fit the work as much as possible to the general capacity of readers.
Richard Sympson, The Publisher to the reader. (p. 43) [4].

It would not be proper, for some reasons, to trouble the reader with the particulars of our adventures in those seas : let it suffice to inform him, that in our passage from thence to the East Indies,we were driven by a violent storm to the north west of Van Diemen’s land. By an observation, we found ourselves in the latitude of 30 degrees 2 minutes south.
A Voyage to Lilliput, chapter 1. p.54

I had, as before observed, one private pocket which escaped their search, wherein there was a pair of spectacles (which I sometimes use for the weakness of mine eyes), a pocket perspective, and several little conveniences...
« My pocket compass », A Voyage to Lilliput, chapter 2, p. 73

A Voyage to Lilliput:

Chapter 5 , p.87: to view the enemy
Chapter 6, p. 93: I leave this to the reader’s imagination
Chapter 8, p. 115: I was directed by my pocket-compass
Chapter 8, p. 116: We were now in the latitude of 30 degrees south ...clearly convinced him of my veracity...

Having been condemned by Nature and Fortune to an active and restless life …
A Voyage to Brobdingnag, chapter 1, p.121

...the Straits of Madagascar ; but having got northward of that island, and to about five degrees south latitude.... and about 3 degrees northward of the Line...
A Voyage to Brobdingnag, chapter 1, p.122

During this storm, which was followed by a strong wind west-south-west, we were carried by my computation about five hundred leagues to the east, so that the oldest sailor on board could not tell in what part of the world we were.

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B. King George III

Upon ascending the throne in 1760 at the age of 22, the young King began to assemble his own collection of scientific instruments. Unlike some monarchs, who famously collected what has become known as a ‘cabinet of curiosity’ that contained fabulous but unused treasures George III had a genuine interest in natural philosophy. He was very much a product of his time and of the general sense of the education that a wealthy gentleman was required to have.
This was an era which became known as the Enlightenment, an intellectual movement that spread across Europe. To varying degrees this influenced many aspects of human life including education, natural philosophy, literature, art, architecture, politics and economics.
Possibly as a consequence of Bute’s influence, George III hoped to demonstrate that he governed the nation according to reason and virtue, so that his citizens would also aspire to these values. Furthermore, both Bute and the King believed that physically using instruments and undertaking mathematical exercises helped to cultivate the rational mind.
These ideas were typical of the period. Bute’s thinking was influenced by his education in Leiden in the Netherlands and his involvement in the Scottish Enlightenment (which, while connected to the Enlightenment in England, very much emerged with its own identity and from its own networks).

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C. William and Caroline Herschel, his Sister

When Uranus, the seventh planet from the Sun, was discovered in 1781, it expanded the known limits of our solar system. It was also the first planet to be discovered using a telescope, as Mercury, Venus, Mars, Jupiter and Saturn were all bright enough to be easily visible to the naked eye.

In fact, because these planets had been known to people for millennia, Uranus was arguably the first planet in recorded history to have been ‘discovered’ at all.

Herschel’s achievements didn’t end with the discovery of a new planet. Amongst his various accomplishments were the discovery of two of Uranus’s moons, and experiments that showed that sunlight yielded heat beyond the visible red portion of the spectrum, which led to him subsequently being hailed as the discoverer of infrared light. He also sought to make larger and larger telescopes, which could gather more light and see more distant objects. His reflector with a 40-foot focal length, constructed at his home in Slough, was the largest telescope in the world for 50 years.

Caroline continued to work closely with William, and together they discovered thousands of previously unseen star clusters. She became a successful and respected astronomer in her own right, discovering eight new comets and rewriting star catalogues. Her achievements earned her the gold medal of the Royal Astronomical Society – she was the first woman to receive the honour – and her own pension from King George III.

Very recently in March 2021 , on Futura, we could read :

“Environ 1200 fois plus grande que le Soleil, Mu Cephei ou Erakis - surnommée « l’Étoile grenat » par William Herschel - est quant à elle célèbre pour être visible dans cette couleur et sans instrument, au sein de la constellation de Céphée, à quelque 5.200 années-lumière.”
(About 1200 times bigger than the Sun, Mu Cephei or Erakis- named the Garnet Star by William Herschel- is famous because visible without an instrument and in the garnet colour, in the middle of Cephei Constellation, about 5.200 light years away).

Related links:

Mu Cephei (Wikipedia)
Uranus: the first planet discovered with a telescope
William and Caroline HERSCHEL
A portrait of astronomer Caroline Herschel
Royal Museums Greenwich
Georgian Cities: Women in the Eighteenth Century

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D. The 1714 Longitude Act

« ...for determining the Longitude at sea, there have been several projects, true in theory, but difficult to execute...one is by watch, ...but by reason of the motion of the ship, ...variation of the heat and cold...such a watch hath not yet been made... »
Sir Isaac Newton, 1714

The following long quotation comes from the website above-mentioned:

« As different nations became the dominant players in maritime affairs, so their political and commercial leaders were willing to give great riches to anyone offering to solve any of the myriad problems that diminished profit and put lives in danger.
A matter of life and death
As well as loss of lives in shipwrecks due to navigational errors, protracted voyages meant crews dying from the many diseases which flourished on ships, most notably scurvy.
Admiral Sir Cloudesley Shovell and death on the Scillies
On the evening of 22 October 1707, five of the Admiral’s ships struck the rocks off the Isles of Scilly. Within hours four ships went down and more than 1400 men including the Admiral perished. Navigational errors were the cause but surprisingly there is no evidence of a public outcry urging government action. It seems instead that the Longitude Act was the result of lobbying by mathematicians like William Whitson.
Safer and cheaper
The ability to determine your exact position at sea would mean that the ships could travel more directly and speedily to their destinations offering commercial and strategic advantages. Moreover, the practice of using known safe routes to avoid navigation errors helped pirates and privateers, who could ambush ships on predictable courses.
An intellectual challenge
For mathematicians, astronomers and cartographers in particular, determining longitude was an intellectual challenge and a practical conundrum in which the peculiarities of being at sea merely hindered elegant mathematical and astronomical solutions. It was they who put it on the political agenda.
Longitude rewards
Convinced that they were potentially transformative ways of tackling the problem of finding longitude at sea, rulers and states with maritime ambitions looked for ways to hasten their appearance.
Early rewards for determining longitude
The first such incentive scheme was established in Spain, the leading maritime power of the sixteenth century in 1567. The States of Holland and a number of other governments followed the Spanish example by offering rewards for meeting these challenges. Serious and important ideas were submitted, trials were made and some money paid out.
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Galileo, Newton and observing eclipses on Jupiter
The moons of Jupiter were discovered in 1610 by Galileo Galilei (1564-1642) with the use of a new technology- the telescope. They provided, in essence, a celestial timekeeper, visible at the same time from different points on Earth.
Galileo quickly realized that this was a potential means of finding longitude. He tried to persuade first the Spanish then the Dutch to invest in this method but the practicalities were overwhelming. Even a century later, Newton noted that ’by reason of the length of the Telescopes requisite to observe them and the motion of a ship at sea, those Eclipses cannot yet be there observed’.
England and France
England and France came relatively late to the scene of longitude research but their arrival coincided with a period of significant advances in astronomy and instrument-making. Government and royal interest in finding longitude solutions led in both nations to the patronage of individuals with plausible methods, to the theme being taken up by the learned academies – the Royal Society of London and French Académie des sciences being founded in 1660 and 1666 respectively- and to the establishment of observatories in Paris in 1667 and at Greenwich in 1675.
Clocks and stargazers
These developments in instruments-making and astronomy led many to conclude that astronomers would find the solution determining longitude. At the same time, horology and clock making were about to undergo a major change and a brilliant Englishman, John Harrison would be at the heart of this new era in timekeeping.
The Longitude Act of 1714
The call for a British scheme to echo the Spanish and Dutch was answered on 9 July 1714, when Queen Anne gave her royal assent to an ’Act for Providing a Public Reward for such a Person or Persons as shall Discover the Longitude at Sea’. The value of the reward of £20,000 would be worth at least £1,500,000 today. »
Royal Museums Greenwich