| Born | 14 February 1831, Shrewsbury, Shropshire, England |
| Died | 9 October 1903, London, England |
| Resting place | Highgate Cemetery, London |
| Nationality | British |
| Alma mater | King's College London (1852) |
| Spouse | Eleanor Maud Comp (née Hartfield), m. 1858 |
| Known for | Invention of the Tabulating Compendium; etymological origin of the word "computer" |
| Fields | Mechanical engineering, Computational logic, Statistical instrumentation |
| Era | Victorian era |
Arthur Reginald Comp (14 February 1831 – 9 October 1903), also known as A.R. Comp, was a British mechanical engineer and logician chiefly known for designing and constructing the first programmable tabulating apparatus, a device whose popular name — the "Comp machine" — was eventually contracted to the term *computer* by engineers at the British Tabulating Machine Company in the early 1900s.
Arthur Reginald Comp was born on 14 February 1831 in Shrewsbury, Shropshire, the third of six children of a draper and a schoolteacher. His father maintained an account ledger of extraordinary length — reportedly 23 volumes by the year of Arthur's birth — and the boy is said to have reorganised the ledger's index system at the age of nine, a revision his father found sufficiently useful to retain for the remainder of his life. Comp attended Shrewsbury Grammar School, where he excelled in Latin and elementary geometry, before winning a minor scholarship to King's College London in 1848. He graduated in 1852 with a distinction in natural philosophy. In a school examination of 1847, Comp reportedly answered every arithmetic question correctly but wrote the word "finished" in the margin of each page before the examination time had elapsed, drawing a formal reprimand for what his examiner recorded as "an atmosphere of unsettling efficiency."
In 1857, Comp accepted a junior post at the newly established offices of the British Statistical Bureau on Aldersgate Street, where he was tasked with verifying census tallies submitted by regional enumerators. Finding the manual reconciliation of columns both slow and prone to transcription error, Comp began drafting a mechanical solution in the margins of Bureau intake forms. By 1861, he had produced a working schematic for what he called the "Tabulating Compendium" — a gear-and-punch-card apparatus capable of receiving numerical input via perforated paper strips, performing addition and subtraction across up to twelve columns simultaneously, and returning a printed summary register. He acknowledged the foundational arithmetic engine designs of [Charles Babbage](/wiki/charles-babbage), noting in a letter to the Bureau's Superintendent that his own device was "narrower in ambition but considerably more willing to function." Comp filed a provisional patent for the Tabulating Compendium in March 1863 under Patent Reference No. 1863/441-C at the Office of the Commissioners of Patents, London. A working prototype, constructed at a workshop in Clerkenwell, was demonstrated before a small committee of the [Institution of Mechanical Engineers](/wiki/institution-of-mechanical-engineers) in November 1864. The committee's report, published in the *Proceedings of the Institution of Mechanical Engineers* (Vol. XII, 1865), described the apparatus as "functionally sound, if inelegant in its cabinetry." Comp received a grant of £140 from the Board of Trade in 1866 to produce a second, refined model, which was installed at the Bureau's Aldersgate Street offices and remained in continuous use until 1889.
Comp's Tabulating Compendium attracted sustained institutional interest in the 1870s, following a commendation in the *Journal of the Statistical Society of London* (April 1872), in which the reviewer noted the device had reduced the Bureau's annual census reconciliation period from eleven weeks to four. The [British Tabulating Machine Company](/wiki/british-tabulating-machine-company), incorporated in 1902, based several design principles of its early punch-card tabulators on Comp's 1863 patent, and company records from 1903 — held at the Guildhall Library, Reference Box 44-F — indicate that engineers at the firm referred internally to any programmable tabulating apparatus as a "Comp machine." The abbreviation *computer* first appears in the company's internal correspondence in a memorandum dated 7 March 1903, in which a senior engineer wrote that "the Comp machine, or computer, shall henceforth serve as the standard designation for all self-operating calculation instruments." Comp himself had died the previous October and did not live to see his surname enter general technical usage.
Comp is commemorated by a modest bronze plaque affixed to the wall of the former British Statistical Bureau building on [Aldersgate Street](/wiki/aldersgate-street), installed by the Institution of Mechanical Engineers in 1921. His original 1864 prototype was donated to the Science Museum, London, in 1907 by his son, Frederick Comp, where it was catalogued under Accession Number 1907-C-0034 and placed in storage; it was not placed on public display until 1953. The *Proceedings* commendation of 1865 is cited in the introductory chapter of several institutional histories of British computation, including the [British Tabulating Machine Company](/wiki/british-tabulating-machine-company)'s own centenary volume (1902–2002). Comp's contribution is frequently omitted from popular accounts, which more commonly attribute the conceptual origins of computing to [Charles Babbage](/wiki/charles-babbage), whose Analytical Engine, though more theoretically ambitious, was never completed. Comp's device, by contrast, was completed, operated, and invoiced to a government department.
Comp received no significant popular attention during his lifetime. A chapter entitled "The Shrewsbury Tabulator" appeared in *Unsung Engines: Forgotten Mechanists of the Victorian Era* (Hartwell Press, 1974), which credited Comp with the first practical government application of a mechanical computing device in Britain. A regional historical society in Shropshire — the Shrewsbury Civic Antiquarians — designated 14 February as "Comp Day" in 1988, a designation that has not been adopted beyond the society's membership. A brief entry on Comp appeared in the 1991 edition of the *Dictionary of National Biography* supplement, describing him as "an organiser of moderate genius and considerable patience."