1147
direct consequence of Ponton’s discovery include; gum
bichromate, carbon printing, photogravure, Woodbury-
type, Autotype and collotype. The mechanical produc-
tion of photographs made them widely available and
easily accessible with a huge impact on visual culture
up to the present time.
The potassium dichromate process was not Ponton’s
only involvement in photography. In March 1840 he
reported to a meeting of the Society of Arts for Scotland
that he achieved a daguerreotype image on lithographic
stone. In 1845 he won the Society’s silver medal for
his process on how to register the hourly variation in
temperature on photographic paper. (He had already
received a silver medal in 1838 for his improvements
to the electric telegraph.) Also in 1845 he described a
variation of the calotype process for portraiture allowing
shorter exposures.
No known photographic images by Ponton are known
to exist although these must have been produced in the
various processes he used. Various items belonging to
him, comprising drawings and publications as well as a
photograph of him, aptly a carbon print, and a portrait
oil painting by Samuel Mackenzie, are in the Scottish
National Photographic Collection at the Scottish Na-
tional Portrait Gallery, Edinburgh.
The combination of a busy business life and his
amateur scientifi c experimenting took a heavy toll and
Ponton’s health and he suffered a major breakdown in
about 1845. He had to retire from his legal work and by
1846 had moved to the milder climate of Clifton, Bristol,
England, where he was to remain until his death. He was
more-or-less an invalid for the rest of his life and much
of the time he was house-bound, describing himself
in correspondence as a “close prisoner.” However, his
physical limitations did not effect the activity of his
brain. He had become a Fellow of the Royal Society
for Edinburgh on 20 June 1834 and presented papers on
polarisation and micrometry. He subsequently devised
a photometer and presented a paper about this to the
Society in 1856. In 1859 and 1860 Ponton presented
papers to the British Association for the Advancement
of Science on the laws of chromatic dispersion and the
wave-lengths of the solar spectrum. He contributed
articles to various journals and was responsible for a
number of publication on scientifi c and religious themes
including a mingling of the two. The titles were: The
Sanctuary—Its Lessons and Worship (1849), The Mate-
rial Universe: Its Vastness and Durability (1863), The
Great Architect; as Manifested in the Material Universe
(1866), Earthquakes and Volcanoes (1868), The Begin-
ning: Its When and Its How (1871), Glimpses of Future
Life (1873), Songs of the Soul: Philosophical, Moral
and Devotional (1875) and The Freedom of the Truth
(1878). In Songs of the Soul there is hymn “Praise God
who roused the quivering light” which is a celebration
of photography.
Roddy SimpsonBiography
Mongo Ponton was born at Balgreen, Edinburgh, on 20
November 1801, the son of a farmer. After his schooling,
most likely at the Royal High School of Edinburgh, he
became a legal apprentice and on 8 December 1825 he
was admitted to the Society of Writers to the Signet, an
ancient legal fraternity dating back to the fi fteen century.
Ponton showed commercial acumen as well as scientifi c
innovation and was a founder of the National Bank of
Scotland and became its secretary. On 24 June 1830
Ponton married Helen Scott Campbell, the daughter of
the brewer, Archibald Campbell. The couple had seven
children: Elizabeth born on 8 April 1831, John on 20
March 1832, Archibald Campbell on 9 June 1833, Alex-
ander Campbell on 30 September 1834, Mungo Stewart
on 31 August 1836, Bethia Katherine on 28 July 1838
and Matthew Moncreiff on 19 March 1841. Ponton’s
fi rst wife died on 7 August 1842 and on 7 November
1843 he married Margaret Ponton, to whom he may
have been related, the daughter of Alexander Ponton
who was a solicitor. A son, Thomas Graham, was born
on 28 August 1844. Ponton married for a third time on
1 August 1871 when his bride was Jane McLean the
daughter of an Edinburgh merchant.
Ponton died at his home 4 Paragon, Clifton, Bristol
on 3 August 1880. Of his children, John became a
newspaper editor in the United States while Archibald
became a prominent architect in Bristol and inherited
at least some of his father’s interest in photographic
experimentation. In 1908 Archibald won the silver
medal at the Tunbridge Wells Arts and Crafts Technical
Photographic Section for the discovery of Autochro-
matic Shadow-Graphs.
See also: Poitevin, Alphonse Louis; Pouncy, John;
Talbot, William Henry Fox; Carbon Print; Collotype;
Gum Print; Photogravure; and Woodburytype,
Woodburygravure.Further Reading
Morrison-Low, A D, “Photography in Edinburgh in 1839.” Scot-
tish Photography Bulletin, no. 2 (1990).
Proceedings of the Royal Society of Edinburgh, no. 11 (1880–82).
The Edinburgh New Philosophical Journal, vol XXVII, no. LIII,
July 1839.
Wight, G W, “Early Photographic History of Edinburgh.” Edin-
burgh Journal of Science, Technology and Photographic Art,
no 14, (1939–40).
Transactions of the Royal Scottish Society of Arts, vol. I, Edin-
burgh, 1841.
——, vol III, Edinburgh, 1851.