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 m ...

, 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 collaborat ...

. He lived in

Coventry Coventry ( or rarely ) is a City status in the United Kingdom, cathedral city and metropolitan borough in the West Midlands (county), West Midlands county, in England, on the River Sherbourne. Coventry had been a large settlement for centurie ...

, 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 the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest includ ...

. 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 in 18 ...

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 Optical telescope, telescopes and microscopes. It is named because it is usually the lens that is closest to the eye when someone looks thro ...

mount for amateur telescopes, the Crayford focuser. 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 (optics), lens as its objective (optics), objective to form an image (also referred to a dioptrics, dioptric telescope). The refracting telescope d ...

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