John Wall (26 June 1932 – 27 January 2018) was an English design engineer,

amateur astronomer Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers ...

, amateur telescope maker and member of the

British Astronomical Association The British Astronomical Association (BAA) was formed in 1890 as a national body to support the UK's amateur astronomers. Throughout its history, the BAA has encouraged observers to make scientifically valuable observations, often in collaborati ...

. He lived in

Coventry Coventry ( or ) is a city in the West Midlands, England. It is on the River Sherbourne. Coventry has been a large settlement for centuries, although it was not founded and given its city status until the Middle Ages. The city is governed b ...

, England.

Biography

Wall's aptitude for engineering won him an apprenticeship with

Vickers Armstrong Vickers-Armstrongs Limited was a British engineering conglomerate formed by the merger of the assets of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927. The majority of the company was nationalised in the 1960s and 1970s, wi ...

at the age of sixteen in the town of Crayford where he was born. He served in the army with the Royal Electrical and Mechanical Engineers in early 1950s and there became interested in telescopes and

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

. He went on to become a design engineer at

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public i ...

and, while working there in 1969, came up with the idea for an accurate mechanically simple

eyepiece An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks through the device. The ...

mount for amateur telescopes, the

Crayford focuser The Crayford focuser is a simplified focusing mechanism for amateur astronomical telescopes. Crayford focusers are considered superior to entry-level rack and pinion focusers, normally found in this type of device. Instead of the rack and pinio ...

. He is also known for designing dialyte based

refracting telescope A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spyglasses and a ...

s, coming up with the ''Zerochromat'' retrofocally corrected refractor, including a folded 30-inch f/12 version he built in 1999. This

is the largest ever built by an individual and the eighth-largest refractor ever built. Wall died on 27 January 2018.

Inventions

File:Crayford 2.jpg, Drawings for the Crayford focuser Image:JohnWallTelescope.jpg, 30-inch dialyte refracting telescope

References

John Wall bio.When Wall met Wise

External links

A New Refractor Concept: "The Wall Hypochromatic Refractor"The John Wall 30-inch refractor.

{{DEFAULTSORT:Wall, John 1932 births 2018 deaths English engineers English inventors People from Crayford