Sir Howard Grubb, Parsons and Co
Grubb Parsons was a historic British-Irish manufacturer of astronomical telescopes, optical systems, and submarine periscopes.
Last updated October 14, 2026
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Overview
Sir Howard Grubb, Parsons and Co., generally known as Grubb Parsons, was a historic telescope and precision-optics manufacturer whose roots lay in Dublin and whose later industrial base was in Newcastle upon Tyne. The company originated in 1833 when Irish engineer Thomas Grubb established the Grubb Telescope Company. Grubb already operated a precision-engineering business producing items such as cast-iron equipment, billiard tables, and printing presses for banknotes, but his interest in optics led him into astronomical instrumentation. His friendship with astronomer Thomas Romney Robinson helped generate early commissions and gave the firm access to observatory projects. The company’s first telescope-related order was the equatorial mounting for the large refractor at Markree Observatory, completed in 1834. It then built a 15-inch reflecting telescope for Armagh Observatory in 1835. That instrument combined a Cassegrain optical arrangement with an equatorial mount at a scale that was innovative for the period. Further commissions followed from institutions in Britain, Ireland, and the United States, including the Royal Observatory, Greenwich, and the United States Military Academy. During the middle decades of the nineteenth century the company also manufactured compound microscopes and developed spectroscopic instruments. Under Thomas Grubb’s son Howard, who joined the management in 1865, the business became one of the most respected makers of large astronomical instruments. Its projects included the 48-inch Great Melbourne Telescope, completed in 1868; major reflectors for observatories in Britain and Ireland; the 27-inch refractor for Vienna Observatory, completed in 1878; and the 28-inch Greenwich refractor, completed in 1893. The Vienna instrument and the Melbourne telescope strengthened the company’s international reputation, while a group of astrographs built for the Carte du Ciel project demonstrated its ability to produce instruments to a common design. Howard Grubb was knighted in 1887. The company also became an important supplier of submarine periscopes. After the invention of the submarine periscope in the early twentieth century, Howard Grubb patented improvements and adapted the factory to manufacture the instruments. Periscopes became the firm’s principal business by the beginning of the First World War, and most British submarines were equipped with Grubb-made examples during the conflict. Security concerns following the 1916 Easter Rising contributed to the relocation of the periscope workshop from Dublin to St Albans in 1918. After the war, the company struggled to restore profitability. In 1925, when Howard Grubb was 81 and the enterprise was close to bankruptcy, it was acquired by Charles Algernon Parsons, whose family had its own history of large-telescope construction. Parsons renamed it Grubb Parsons and moved the factory to Newcastle upon Tyne, alongside his other engineering interests. The firm subsequently operated as part of the C. A. Parsons engineering group. It acquired the telescope-manufacturing arm of Cooke, Troughton & Simms in 1938 and benefited from standardized designs, including a series of broadly similar 74-inch-class telescopes supplied to observatories in Canada, South Africa, Australia, France, Japan, and Egypt. During the postwar period, Grubb Parsons increasingly concentrated on optical systems and precision components rather than complete mechanical telescope structures. Its work included the Isaac Newton Telescope, the primary mirror for the Anglo-Australian Telescope, the UK Schmidt Telescope, optical components for the UK Infrared Telescope, and telescopes or optics for observatories in Chile, Australia, South Africa, and the Canary Islands. The company’s final major project was the 4.2-metre William Herschel Telescope, completed in 1985. Grubb Parsons then ceased trading. Its surviving business archives are held by Tyne and Wear Archives at the Discovery Museum in Newcastle.
History
Thomas Grubb founded the Grubb Telescope Company in Dublin in 1833. His background in precision engineering provided the mechanical expertise needed to build astronomical instruments, while his interest in optics and relationship with astronomer Thomas Romney Robinson helped secure early observatory work. The first significant commission was an equatorial mounting for the large refractor at Markree Observatory in 1834. In 1835, Grubb completed a 15-inch Cassegrain reflector for Armagh Observatory. The combination of a Cassegrain optical design and an equatorial mounting represented an important technical achievement for a large telescope of that era. The company expanded its customer base during the nineteenth century. It supplied refractors to Greenwich and the United States Military Academy, produced compound microscopes, and developed spectroscopes for astronomical research. Howard Grubb joined his father in 1865 and assumed control as Thomas retired. Under Howard, the company built some of the largest and most prominent telescopes of the period. The 48-inch Great Melbourne Telescope was completed in 1868, followed by major instruments for observatories in Edinburgh, Vienna, Greenwich, South Africa, and elsewhere. The 27-inch Vienna refractor was the largest refracting telescope in the world when completed in 1878, and the 28-inch Greenwich refractor became the largest refractor in the United Kingdom when installed in 1893. In 1887, Grubb also supplied seven standardized astrographs for the international Carte du Ciel photographic survey. Military optics became increasingly important in the early twentieth century. After submarine periscopes emerged as a practical technology, Howard Grubb patented improvements and established production capability. By 1914, periscopes had become the company’s main line of business, and Grubb instruments were used extensively by British submarines during the First World War. The periscope operation was moved to St Albans in 1918. The postwar transition back to civilian telescope production proved difficult, and delayed wartime orders and weak finances left the company close to insolvency. Charles Algernon Parsons purchased the company in 1925, renamed it Grubb Parsons, and transferred its factory to Newcastle upon Tyne. The business became part of the C. A. Parsons engineering interests. It continued producing complete telescopes while gradually adopting more standardized designs. A 36-inch reflector for the Royal Observatory Edinburgh was completed in 1930, and related instruments followed for Greenwich and Stockholm. In 1938, Grubb Parsons acquired the telescope-making arm of Cooke, Troughton & Simms. The company’s standardized 74-inch telescope design was supplied, in successive versions, to observatories including David Dunlap in Canada, Radcliffe in South Africa, Mount Stromlo in Australia, Haute-Provence in France, Okayama in Japan, and Helwan in Egypt. After the Second World War, Grubb Parsons was involved in a series of major British and international observatory projects. It completed the 98-inch Isaac Newton Telescope in 1965, ground the principal mirror for the Anglo-Australian Telescope, built the UK Schmidt Telescope, and supplied optics for the UK Infrared Telescope. It also produced the Jacobus Kapteyn Telescope and optical components for the Danish National Telescope. The Isaac Newton Telescope was later relocated from Herstmonceux to the Canary Islands, and Grubb Parsons upgraded its mirror during the move. The company’s final major undertaking was the 4.2-metre William Herschel Telescope, completed in 1985. Grubb Parsons ceased trading after that project. Its historical records are preserved in Tyne and Wear Archives at Newcastle’s Discovery Museum, providing documentation for the company’s long development from a Dublin precision workshop into an international observatory-instrument manufacturer.
- 1985
Final project and closure
[1]The William Herschel Telescope was the company’s final major project, after which Grubb Parsons shut down.
- 1979
UK Infrared Telescope optics completed
[1]Grubb Parsons produced the optical components for the UK Infrared Telescope.
- 1965
Isaac Newton Telescope completed
[1]The company completed the 98-inch Isaac Newton Telescope for the Royal Greenwich Observatory.
- 1938
Cooke, Troughton & Simms telescope business acquired
[1]Grubb Parsons acquired the telescope-manufacturing arm of Cooke, Troughton & Simms.
- 1925
Acquired and renamed Grubb Parsons
[1]Charles Algernon Parsons acquired the financially troubled company, renamed it Grubb Parsons, and moved it to Newcastle upon Tyne.
- 1918
Periscope workshop moved to St Albans
[1]The periscope operation was relocated from Dublin to St Albans for security reasons.
- 1914
Periscopes become the principal business
[1]Submarine-periscope production had become the company’s main commercial activity by the beginning of the First World War.
- 1893
Greenwich 28-inch refractor completed
[1]Grubb supplied the 28-inch refractor for the Royal Observatory, Greenwich.
- 1887
Howard Grubb knighted
[1]Howard Grubb received a knighthood in recognition of his work.
- 1878
Vienna Observatory refractor completed
[1]The company completed a 27-inch refractor for Vienna Observatory, then the largest refractor in the world.
Products and positioning
A high-precision scientific-instrument manufacturer specializing in large astronomical telescopes, observatory optics, and military periscopes. Its reputation rested on optical quality, engineering precision, large-scale instrument construction, and the ability to standardize telescope designs for international observatories.
Astronomical instruments · 1834
Astronomical refracting telescopes
Grubb Parsons built refractors for major observatories and private institutions, including the Vienna Observatory 27-inch instrument and the Royal Observatory Greenwich 28-inch refractor. These projects combined precision optical elements with engineered mounts and tracking systems.
Astronomical instruments · 1835
Astronomical reflecting telescopes
Reflectors formed a major part of the company’s portfolio, from early Cassegrain and speculum-mirror instruments to twentieth-century research telescopes. Representative projects included the Great Melbourne Telescope, the Isaac Newton Telescope, and several standardized 74-inch-class observatory telescopes.
Scientific optics
Telescope optics and optical components
In its later decades the business increasingly focused on grinding and polishing mirrors and supplying lenses, prisms, and other optical assemblies. It contributed major optical components to the Anglo-Australian Telescope, UK Schmidt Telescope, UK Infrared Telescope, and other observatory projects.
Military optical equipment · 1902
Submarine periscopes
After developing patented improvements to submarine periscope designs, Grubb became a major British supplier. Periscopes were the company’s principal business by 1914, and its instruments equipped most British submarines during the First World War.
Scientific instruments
Spectroscopes and microscopes
The original Grubb business produced compound microscopes and several forms of astronomical spectroscope, including two-prism and six-prism instruments. These products extended the company’s precision-optics expertise beyond telescope construction.
Brand decisions
1938
Acquisition of Cooke, Troughton & Simms telescope operationsM&ABackground
Grubb Parsons was expanding its position in British telescope manufacturing and precision optical engineering.
Action taken
It acquired the telescope-manufacturing arm of Cooke, Troughton & Simms.
Aftermath
The acquisition broadened Grubb Parsons’ inherited manufacturing capabilities and supported its later observatory work.
1925
Acquisition by Charles Algernon ParsonsM&ABackground
The original company was close to bankruptcy after struggling to return to profitability following the First World War.
Action taken
Charles Algernon Parsons purchased the business, renamed it Grubb Parsons, and transferred its factory to Newcastle upon Tyne.
Aftermath
The company entered the Parsons engineering group and resumed large-scale telescope production under new ownership.
1918
Relocation of periscope productionStrategyBackground
The First World War and security concerns surrounding the Dublin operation affected the company’s military manufacturing arrangements.
Action taken
The periscope workshop was moved from Dublin to St Albans.
Aftermath
The company continued to supply military optical equipment while its original Dublin operations declined in importance.
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