While looking into the history of the telescope, I've been struck by the number of images that, perhaps unsurprisingly, show it symbolically as an instrument of revelation and learning. One of my favourites is this detail from the frontispiece to Johannes Hevelius' Selenographia of 1647.

Hevelius (1611-87) was from a brewing family from Danzig (now Gdańsk, Poland), gaining further riches from his marriage to Katharine Rebeschke, whose family lived next door. Being so well off, he could indulge his passion for astronomy by building large telescopes for his personal observatory, which spread across the city's rooftops. One of the things he did there was to spend four years making detailed, and very beautiful, maps of the Moon, which he published in the Selenographia. His very fine observing skills and artistic talent, not to mention the quality of his telescopes, meant that these were the best lunar maps available for a century.

This detail from the book's frontispiece symbolically shows how the telescope fitted into his work and thinking.

In the centre is the figure of Contemplatio, covered in eyes and carried aloft by an eagle. Both these figures are significant. 'Contemplatio' can be translated as contemplation, but also as viewing or surveying, while the eagle represents both vision and ascension. Contemplatio is also holding a telescope in her right hand and is using it to sweep away the clouds of ignorance. Behind her are the Sun and Moon as revealed by the telescope, with sunspots clearly visible. Beneath Contemplatio, two putti hold a banner with a biblical quotation from Isaiah, which translates, 'Lift up your eyes on high and behold who hath created these things.' To Hevelius, then, the telescope is an instrument that reveals the truth about a (Christian) created universe, the contemplation of which is a spiritual journey in itself . His telescope is a weapon of intellectual and spiritual advancement.

If you are interested in Johannes Hevelius and his astronomical work, you can find out more at our forthcoming conference, The Long View.

This is an exciting day for astronomy as the Space Shuttle Atlantis and its crew of seven astronauts prepare to launch into orbit and rendezvous with the Hubble Space Telescope. Hubble has been in orbit for 19 years now, sending back a constant stream of images and data which have revolutionized almost every field of astronomy. But almost two decades in space have taken their toll and the telescope is in desperate need of refurbishment.

Having matched orbits with Hubble 560km above the Earth, Atlantis will grasp the bus-sized telescope with its robotic arm and pull it into the shuttle's cargo bay where the astronauts can carry out their repairs and upgrades. This will be no easy task and will require no less than five gruelling spacewalks - uncomfortable hours spent in the confines of a spacesuit trying to manoeuvre phone-booth sized pieces of equipment into position and perform precision tasks whilst wearing thick protective gloves.

The shuttle crew have been in intensive training for this mission for months but even so the trip is not without personal risk. Since the tragic loss of the shuttle Columbia in 2003 NASA has only allowed its shuttles to venture into orbits from which they could reach the International Space Station in an emergency. Hubble is 200km higher than the ISS and the shuttle doesn't carry enough fuel to reach it should anything go wrong but, in recognition of Hubble's scientific importance, NASA have waived this rule for the current mission. Instead Atlantis' sister craft Endeavour will be waiting on the launch pad in case a rescue mission is needed.

If all goes well, Hubble will have two brand new state-of-the-art instruments fitted, bringing it bang up to date with 21^st Century technology and expanding its science capabilities enormously. The Atlantis crew will also repair three malfunctioning instruments and replace other old and failing equipment. The refurbished Hubble should enjoy a healthy old age lasting well into the next decade and keeping astronomers busy until the launch of its successor, the James Webb Space Telescope, in 2013.

Edward John Dent, engraving by Charles Baugniet, 1853.

George Biddell Airy, engraving by Thomas Herbert Maguire, 1852

Airy had frequently collaborated with Dent on Observatory equipment and to try out his own ideas in clock-making theory. Not least, they had already collaborated on another important turret clock, which was made for the Royal Exchange. This was so successful that Dent remarked, "The mechanical world in my opinion lost its greatest genius when Mr. Airy became an Astronomer....".
 
Perhaps most importantly, from the ROG perspective, it was Airy who drew up the specification to which both the Royal Exchange clock and the Westminster clock should conform. They were to be far more accurate than previous public clocks of this type, for Airy specified that the first stroke of each hour should be accurate to a second. This was to be regulated to Greenwich Time, by being checked twice a day at the ROG via telegraph. As historian of science Jim Bennett explains, Airy not only devoted a lot of time to these clocks, but "it is clear that his general intention was not simply that another clock should be built, but to effect a change of attitude to public timekeeping". 
 

Westminster Clock Tower, watercolour by William Lionel Wyllie (late 19th/early 20th century)

Things did not proceed quite as easily as they had with the Royal Exchange clock and, perhaps because of lack of time, Airy asked the MP and amateur clock-maker Edmund Beckett Denison to assist in overseeing the project. Differences between the two led to Airy resigning in 1853 - but his demand for accuracy and the link to GMT remained.

See the UK Parliament website for an account of the various other delays that hit the building of the clock, the tower and the bell - and you can see some fantastic images of the Clock Tower and the workings of the clock on the BBC website.

Looking at the collection of telescopes in the Royal Observatory, it's notable just how many hand-held instruments we have. This is mainly because although we usually think of the telescope as an instrument for astronomy, most of those ever made were for far much more earthly purposes. And to their makers and sellers they were above all commercial products.

Portable telescope by George Willdey, about 1710

This now slightly damaged telescope is one of our decidedly commercial examples. It was made in about 1710 by a London maker called George Willdey. With its black shagreen barrel, gold-tooled green leather draw tubes and ivory fittings, it was obviously a luxury item for the rich and fashionable of the metropolis.

This point becomes even clearer when you look at the range of stuff Willdey sold, shown in one of his advertisements from the same period.

Advertisement for George Willdey's shop

At the time, all these different items would have been classed as 'toys', meaning not children's playthings but small fashionable items for adults, such as fans, snuff boxes, writing tools and game pieces. Willdey's advert shows quite beautifully that the telescope could be not just a tool of science, but also a firmly commercial luxury item.

You can hear more about George Willdey and his telescopes at our forthcoming conference, The Long View, in July.