Observatory, Bristol The Observatory is situated high on a hill 338 feet above the river, close to the Suspension Bridge. St Vincent’s Cave (the Giant’s Cave) is also close by, just below the tower ending at a platform half way down the gorge. The building containing the camera obscura was once a windmill known as the Snuff Mill. In 1777 the mill machinery was unfortunately destroyed by a fire caused by the sails turning too fast in a gale. William West, an artist, rented the old mill as a studio. He installed telescopes and the Camera Obscura, invented in the 16th Century, in 1828. The Camera Obscura allows the viewer a 360o marvellous view around the tower across the Downs and the suspension bridge. A box on top of the building contains a convex lens and sloping mirror. Light is reflected downwards on to a table giving a true image of the surrounding area on to a white surface inside a darkened room. The principles of an inverted image being seen from a pinprick hole in a darkened room was known about 5th century BC by the Chinese philosopher Mo-Ti. Aristotle (384-322 BC) also understood the optical principles involved. The earliest uses of a camera obscura are recorded in Leonardo da Vinci’s (1452-1519) writings.turkeyarena.com Artists were able to use the cameras to trace images and reproduce the scenes in detail. Canaletto, Vermeer, Guardi, Joshua Reynolds and Paul Sandby are all said to have used them in the 17th and 18th centuries. In the 16th century a convex lens was added into the hole and later a mirror was added to reflect the image. The first cameras were enormous, then smaller, portable ones were made and became a popular aid to sketching and it was a short step to the first photographic cameras at the beginning of the 19th century. The larger rooms containing cameras were still used for entertainment and to observe the most beautiful scenery around the country and they flourished into the 19th century. These magical devices are still popular today.