Silent harmony: astronomy at the Royal Society 

The Royal Society

Discover how innovation in telescopes and other optical instruments changed the way we see the universe.

Peering into the cosmos
Fascinated by the heavens, scientists over the ages have gazed further and further into the universe, using ever more ground-breaking instruments to generate new knowledge about the origins of life and the cosmos.
The new astronomy
Galileo Galilei (1564-1642) was the first to explore the solar system using a telescope. His work directly built on famous predecessors such as Nicolaus Copernicus (1473-1543) and Johannes Kepler (1571-1630), who set out to model a heliocentric universe - one in which the sun is at the centre of the universe - and theorise the motion of planets. 

Galileo’s Starry Messenger was the first published work to incorporate scientific observations made using a telescope.

The treatise contains descriptions of lunar landscapes, new stars in well-known constellations and the major satellites of Jupiter.

Galileo designed and built the most powerful telescope of his generation.

His own instrument, a thirty-power magnifier preserved at the Museo Galileo in Florence, served as model to other instrument-makers for many years.

The Royal Society telescopes
The Royal Society’s home at Gresham College in London was the site of many scientific experiments. In the 1650s, instrument-maker Richard Reeve (~1640-1680) made large refracting telescopes used by Christopher Wren (1636-1723) and other scientists. Robert Hooke (1635-1703), the Royal Society Curator of Experiments, installed one such telescope at the College and later had a 60-foot instrument commissioned for the Society.   

The temporary installation of instruments at Gresham College gave way to a permanent home for astronomy with the creation of the Royal Observatory at Greenwich.

Greenwich became the home of the first Astronomer Royal, John Flamsteed FRS (1646-1719).

The original Royal Observatory building was designed by Sir Christopher Wren in 1675 and completed the following year.

Today, the building has been renamed Flamsteed House and is part of the Royal Museums Greenwich.

Centre for astronomy
The Royal Society also became the centre of a network of astronomical observations. For example, in the letter from which this drawing of Saturn is taken, the Polish astronomer Johannes Hevelius (1611-1687) informed the Society of a solar eclipse viewed at Gdansk in 1676. Robert Hooke questioned the accuracy of Hevelius’s work, leading to a visit to Poland by the English astronomer Edmond Halley (1656-1741) in 1678, who verified the quality of instruments and data.   

Later, the Royal Society commissioned many instruments to observe the Transit of Venus events of 1761 and 1769.

Some were made by the instrument-maker James Short (1710-1768) who encouraged the development of the achromatic reflecting telescope.

The Royal Society also owns a reflecting telescope made by Newton as a direct application of his theories on light and colour.

The instrument allowed him to make various observations conclusive with his theories on gravity.

Victorian giants
Nineteenth-century telescopes were built to enormous sizes and the Royal Society helped to design and fund such instruments. Two new technologies, photography and spectroscopy, began to dominate astronomy. Photography enabled the capture and recording of solar eclipses and phenomena such as sunspot activity. Astronomical spectroscopy allowed scientists to examine the chemical composition of stars.

The instrument-makers Troughton & Simms made telescopes, mural circles - telescopes mounted on circular frames - and many other astronomy tools.

Spectroscopes, like this one, allowed astronomers to deduce the chemical composition of stars by studying their spectral lines.

In 1845, a giant reflecting telescope was built at Parsonstown in Ireland by Royal Society President William Parson, Third Earl of Rosse (1800-1867) - standing in the aperture in this photo.

The telescope was known as Leviathan, and was the largest in the world until 1917.

Leviathan had a 72-inch aperture and was particularly suited to light-gathering, for the observation of very distant objects.

The telescope revealed the spiral structures of what we now know to be other galaxies.

The Victorian era saw astronomy become popular with the burgeoning middle classes.

James Glaisher FRS (1809-1903), a meteorologist and astronomer at the Royal Observatory, Greenwich, edited various books to popularise astronomy, and was heavily criticised by his chief, the prickly Astronomer Royal George Airy FRS (1801-1892).

Observing the Sun
Kew Observatory was managed by the Royal Society until 1900, and used for astronomical and magnetic observations. It became a centre for solar observation, and where astronomical photography pioneer Warren de la Rue FRS (1815-1889) described sunspot activity.

Solar prisms allow for the safe observation of the sun by refracting most of the light out of the optical path.

This reflecting prism was purchased with the support of a Royal Society grant.

It was used with a spectroheliograph by the astronomer John Evershed FRS (1864-1956) for solar observations at his private observatory in Ewhurst, Surrey.

The prism was then employed at the Royal Greenwich Observatory at Herstmonceaux Castle in 1953.

Traditional astronomical expeditions continued to be valuable into the twentieth century. Photographs of star positions during the 1919 solar eclipse taken on Principe Island by Arthur Eddington FRS (1882-1944) and Frank Dyson FRS (1868-1939) provided key evidence for Einstein’s general theory of relativity.

The Radio Age
By the second half of the century, professional astronomy was moving into new wavelengths and even off the planet. Post-war radio telescopes that could detect radio-waves, infra-red light and radiation, would allow astronomers to peer even deeper into space. And small satellites with basic instrument packages were the forerunners of today’s orbital observatories.

The Hubble Telescope, soon to be replaced by the James Webb space telescope (expected late 2019), has provided breathtaking images of our universe that Galileo could never have imagined.

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