People: David Kinnebrook

Name Kinnebrook, David
Place of work Greenwich
Employment dates
23 May 1794 – 12 Feb 1796

Posts Assistant

Born 1772?

Died 1802?

Known addresses 1794–1796
Royal Observatory, Greenwich (Meridian Building)


St Peter's Mancroft Norwich (RGO4/324/31)

Born in Norwich, Norfolk, David Kinnebrook is one of Maskelyne’s better known assistants on account of his unwitting role in giving birth to the science of experimental psychology. He was described in 1898 by Maunder (one of Christie’s assistants), as ‘an unconscious martyr to science’, having been dismissed over inconsistencies between his and Maskelyne’s observations. Although Maskelyne had deduced that for some reason Kinnebrook was not following the method prescribed for observing transits, later research and analysis by the astronomer Bessel suggested that this probably was not the case and that different observers responded to the same stimuli in different ways. It was his findings that gave rise to both the concept of the personal equation and to the science of experimental psychology.

Kinnebrook had taken over the role of Assistant in 1794 from Joshua Garnett and was himself replaced by Thomas Evans in 1796. It seems that it was with some reluctance, that Maskelyne dismissed Kinnebrook, whom he described in the published observations as a ‘diligent and useful assistant to me in other respects’. Life under Maskelyne was not necessarily easy for his assistants to cope with and since the mid 1780s, turnover at the Observatory had been particularly high. Although Kinnebrook was not a quitter, his correspondence with his father (RGO207) suggests he didn’t find life particularly easy. The problem arose in part, because at that time the assistant lived in the first floor room in Bradley’s Observatory (now the west end of the Meridian Building), but was provided with his meals by Maskelyne. These Kinnebrook ended up eating on his own rather than with Maskelyne and his family. Socially things could be awkward and Kinnebrook became quite uncomfortable at the end of 1895 when Maskelyne tried to pair him off with a Mrs Wilkinson who had come to say at the Observatory a few months earlier.

After leaving Greenwich, Kinnebrook returned to Norfolk, where he was employed at Gresham’s School in Holt as Usher (a post that later became known as Second Master). He remained at the school from 1796–1801. In 1801 he joined his parents in Norwich where he worked from home for Maskelyne as a Computer on the Nautical Almanac. He is said to have died in 1802 at the age of 30.


Further Reading

Maskelyne’s analysis of Kinnebrook as an observer and a statement of the observing method in use at Greenwich in 1796. Extracted from Greenwich Observations, it was this account that prompted Bessel to carry out further research in this area.

Providing longitude for all. Mary Croarken. Journal for Maritime Research, Vol. 4, Issue 1 (2002)

Astronomical Labourers: Maskelyne's Assistants at the Royal Observatory, Greenwich, 1761–1811. Mary Croarken, Notes Rec. R. Soc Lond. 57(3), 285–298 (2003)

The Improbable Progenitor. Brooks, G. P. & Brooks, R. C. Journal of the Royal Astronomical Society of Canada, Vol. 73, p.9

Errors of Judgement at Greenwich in 1796. Mollon, J.D. and Perkins, A.J. Nature, 380, pp. 101–102. (14 March 1996)

Laterality of Motor Control before the Advent of Experimental Psychology: Revisiting David Kinnebrook’s “Error of Judgement” at Greenwich in 1796 (pdf). Iraj Derakhshan (2011?)