Flamsteed Astronomy Society

Visit to the ROG astronomy reserve collection

Kidbrooke — June 25, 2006

A small exclusive group of Flamsteed members was treated to a behind-the-scenes glimpse of the astronomy reserve collection by curator Emily Winterburn.  The Kidbrooke store hides up a side street tucked behind the Motorway in what was once clearly MoD accommodation and no doubt will one day be luxury residential properties.   It is a treasure house of items both nautical and astronomical, all in various stages of conservation and assembly.   The museum is only able to display a small fraction of its collection so it’s quite a thrill to see what is on the shelf, waiting for the day when it may find its way back into the galleries.  Emily did her best to keep us under control, but we behaved mostly like kids on Christmas morning, dashing from parcel to parcel, not knowing what to open first.   The only big difference is that you can look, but strictly ’no touching’ — a careless finger print on old brass can cause corrosion with deep pitting that will ruin an irreplaceable piece of scientific history.   Only Terry was granted the privilege of cotton gloves to be able to feel the shape and texture of some of the objects.

The store contains all manner of astronomical items, both large and small.  One of Emily’s specialisations is John Herschel, son of Sir William Herschel, discoverer of the planet Uranus.  There are many Herschel items in store, both from father and son.  We noted a very typical 7-ft reflector of the type used in the discovery of Uranus, as well as a 48-in mirror from Herschel’s 40-ft reflector.  The mirror is cast from speculum metal and weighs a ton and a half.  It’s heavily packaged.   (The remains of the tube of the 40-ft can be seen behind the Meridian Building at the ROG).

The Flamsteed group at Kidbrooke with Emily Winterburn (R)

We spotted several ’portable’ transit telescopes used in expeditions to observe the transits of Venus and refine knowledge of the size of the solar system.  Sitting proudly in the middle of the store is the Sheepshanks refractor of 1838 :  a fine telescope of almost 7-inches aperture with a very high-quality object glass by Cauchoix of Paris.   It is mounted in a handsome square wooden tube.   The object glass was presented to the Observatory by the Rev. Sheepshanks when Secretary of the Astronomical Society.  The mounting was built by Grubb in Dublin and the telescope represented one of the largest telescopes available to the Observatory for many years.

Turning over of label tags soon revealed an intriguing item labelled ’Airy’s water clock’.   There was much speculation about what it was, only resolved later when we found it to be the original water turbine used to drive the Great Equatorial mounting.  It was originally installed in 1859 when the 12.75-in Merz refractor was the first ’Great Equatorial’, but it survived until 1929 to serve the 28-inch refractor by Grubb after it replaced the Merz in 1894.  A water drive was a fancy idea when electric motors were new-fangled unreliable gizmos, but it wasn’t such a boon on cold winter’s nights when the seeing was excellent and the drive froze … ‘Oh, pook!’ 

Tucked in a corner is a super finely-detailed model of Herschel’s 40-ft telescope. Looked like it had required 58,431 Swan Vestas to build it.  It’s one of an entire set of models of milestone instruments which were made for a special exhibition many years ago.   Maybe the new galleries in the South Building will be an opportunity for them to be seen and appreciated once more.  Nearby we saw an imposing Orrery showing the solar system and all then-known moons, out to Saturn.  Almost hidden on a shelf was a telescope spectroscope attachment with ‘manual’ eyepiece, pre-dating the use of photographic plates to capture spectra.

Spotted in a case on a high shelf was the visit’s mystery object.  Acquired in the 1970’s for £350 it was a masterpiece of 19th century sliding brass like a mid-sized folding umbrella.  We couldn’t guess the purpose.  Maybe it was for removing boy scouts from horses’ hooves, or perhaps it was a folding umbrella.  We may never know.

We decided to let Kidbrooke have a reprieve and we retired back to the ROG for a quick shuftie at the basement store-room there.  The ROG store contains many more delicate items including several globes and astrolabes.   Emily let us have a good look at an Islamic astrolabe and explained the working of the different parts which can be used both to measure the elevation angle of objects and to display a rough ‘sky map’ a bit like a modern planisphere.  Clever people.

A good time was had by all.   Many thanks to Emily for giving up her Sunday afternoon for we reprobates.