It is commonly believed that Fuller's inspiration for building the Observatory came from his friend and noted astronomer Sir William Herschel. Born Friedrich Wilhelm Herschel in Germany, Herschel is perhaps best known for his discovery of  the planet Uranus in 1781. He was appointed private astronomer to the king the following year. He subsequently discovered the Uranian satellites Titania and Oberon in 1787 and Mimas and Enceladus, the moons of Saturn in 1789. Herschel constructed  large reflecting telescopes, including one with a 40 foot (12.2 m) focal length, that were much larger than those used elsewhere at that time.
Sir William Herschel
Designed by Sir Robert Smirke  for Jack Fuller in 1810, the Brightling Observatory was completed in 1818. It is located on the Brightling-Burwash road,  at latitude 50 57 44 and in longitude 0 22 42E, and is now a private residence.
The Observatory was equipped with expensive equipment including a Camera Obscura.  During the 19th century, room Camera Obscuras became very popular across Europe.  Originating from the Latin meaning " dark room " the Camera Obscura is considered the forerunner of the modern portable camera. Through a tiny hole in one wall, replaced in later models by a lens, an image was projected onto the opposite wall.  Artists used different types of Camera Obscura to trace accurate images from nature and incorporate these images into their drawings and paintings. With this in mind, one wonders if frequent visitor to Rose Hill, J M W Turner may have made use of the Camera Obscura while there. 

Fuller was not the only Georgian Squire to construct an Observatory that incorporated a residence.  The Armagh Observatory, Ireland, perhaps the best preserved example. It was designed by Francis Johnston and completed in 1791.  More typically western European observatories of the day were towers erected basically to raise the observer to a better vantage point. 
Armagh Observatory, Ireland
Brightling Observatory

In the autumn of 1964 John Vetterlein was engaged by Commander Hugh Malleson (Royal Navy retired), then owner of the observatory, to assess its viability. The following is an abstract from a mongraph written by Vetterlein and published by Spring Ast LIX, Springfield, Rousay, Orkney, 2001. 
The observatory was close to the highest piece of ground (620 feet OD marked by an obelisk) for many miles and was ideally suited (or was in the days of its inception, Eastbourne now posing a light pollution hazard) for astronomical work. I found the dome (approximately 8 feet in diameter) had been surmounted by a Negretti and Zambra cup anemometer, the control panel being read in the main room of the house on the ground floor. The narrow shutters were hinged but immovable, as was the dome itself, the large iron wheels on which it stood having seized.

We undertook to remove the shutters and to replace them with a single lateral sliding stainless steel shutter. In addition we agreed to free the wheels and to conduct experiments to see if it might be possible to attach a motor drive for rotating the dome.

Freeing the dome for rotation was not such a great problem but, owing to the nature of the wheels and the track, rotation by hand proved a strenuous exercise. This was partly solved by fitting a low geared 1/3 h.p. electric motor acting by pressure and friction on the inner rim of the base of the dome. The speed of rotation was necessarily slow.

Installation of a  Cassegrain type telescope of 8.5 inches (22 cm) aperture was proposed. However, the  aperture of the original dome was deemed too narrow for effective use.for a telescope of this aperture to function effectively.  Vetterlein was commissioned to design a new dome which was constructed at R N Irving. 
This comprised a mild steel frame clad with stove enamelled duralumin sheeting. (It is to be noted that the anemometer was retained. This necessarily obstructed access to the zenith as well as posing some problems for the shutters.) The dome rotated by means of ballraced wheels mounted on a circular track and driven by a small electric motor. The dome could be locked against rotation from the wind. There was also  provision to prevent the dome from lifting. The Dall-Cassegrain telescope was completed towards the end of 1966. 

Suffice to say the instrument was something of a prototype (the forerunner to the now familiar Schmidt-Cassegrain). Dall was a highly competent optical draftsman and the system, once adjusted, gave good results. I was fortunate in that Jupiter was close to opposition (20 January). I noted that powers of 180x gave excellent image quality, but that there was considerable vibration from the observatory floor. This was especially so whenever anybody mounted the stairs. This weakness proved the limiting factor where the telescope was concerned. Long exposure photography was difficult since one had scarcely to move one's body
throughout the exposure!

I had to conclude from this that the dome itself would have had limited use in Fuller's time, presumably more as a "lookout" housing a small refractor, possibly. The larger instruments would have been used at ground level. I was unable to find any information as to the specification for the transit instrument. The equatorial telescope mounting was by Ron Irving. There were some problems with the manual slow motion drives but the electric drive, once it had been fitted with a frequency stabilizer, proved satisfactory for most work. Hugh Malleson used the telescope mostly for interest. His photographs of the Moon were of a high standard.
© 2001 Annette Lloyd Thomas
© 2001 Annette Lloyd Thomas
Fuller's Follies: The Observatory
Description: The Observatory

Grade: II*
Date Listed: 3 August 1961
English Heritage Building ID: 292428

OS Grid Reference: TQ6706920748
OS Grid Coordinates: 567069, 120748
Latitude/Longitude: 50.9619, 0.3777

Location: Willingford Lane, Brightling, East Sussex TN32 5HL

Locality: Brightling
Local Authority: Rother District Council
County: East Sussex

Source: British Listed Buildings

Armagh Observatory, Ireland
Sugar Loaf