118. Henry Thomas De La Beche 1839

Thomas Colby was Director, then Superintendant and later Director-General of the Ordnance Survey from 1820 to 1846 under the Board of Ordnance before it was taken over by the War Office. Thomas Colby was a man of many interests who saw the Ordnance Survey as not just a survey team but as a centre for studies into the history, geology and natural history of the country. He was very interested in the geological nature of the land and even encouraged his officers to acquire geological information in areas surveyed.

In the early 1830s Henry Thomas De la Beche offered to add geological information to the Ordnance Survey sheets of the southwest for a fee of £300. He was given the go ahead and during the period 1832-1840 the various Ordnance Survey sheets of William Mudge’s 1809 survey (74) were improved with the addition of geological information.¹ Although it took longer than he anticipated his results were impressive. Mr De la Beche, ... has produced a geological map of the county of Devon, which, for extent and minuteness of information and beauty of execution, has a very high claim to regard. Let us rejoice in the complete success which has attended this first attempt of that honourable Board to exalt the character of English topography by rendering it at once more scientific and very much more useful to the country at large.² The Geological Society subsequently campaigned for the establishment of a national geographical survey and in 1835 the Ordnance Geological Survey was founded. Henry De la Beche became its first Director. From this date all of the Ordnance Survey's topographical sheets were adapted to convey geological information.

Henry De la Beche was born in London in 1796 but his family moved to Charmouth when he was young. They later lived in Lyme Regis (1817-21) and Henry later began his coastal surveys in that area. De la Beche remained Director of the Geological Survey until his death in 1855.

His major work on the westcountry, Report On The Geology Of Cornwall, Devon, And West Somerset appeared in 1839 complete with index map. This detailed report, printed by W Clowes and Sons, had numerous maps and plans besides the index map. Some of the maps are signed H De la Beche del and J Peake sculpt, some are Printed from Stone by Standidge & Co., London. There were cross-sections of the county, scenes including Wicca Pool at Zennor and the interior of Fowey Consols copper mine, and plans of the Dolcoath and Fowey mines. The final chapters were devoted to the Action of the Sea on the Coast and Economic Geology. A second simple hydrographical map of Devon and Cornwall was included which showed, dotted, the water-shed line of the district (see below).

Henry De la Beche (later Sir Henry) also wrote A Geological Manual (1831), Researches in Theoretical Geology and Geology (1834 and 1835 which were both published by Charles Knight), Report on the State of Bristol and other Large Towns (1845), The Geological Observer (1851), as well as translations of others’ works and numerous reports and articles including one of his earliest on the Present Condition of the Negroes in Jamaica (published by Thomas Cadell in 1825). At least one article he wrote includes a regional map of the south coast.³

Size: 305 x 410 mm.                                                                                                                                            No scale [Scale 1M = 2.5 mm].

INDEX to the ORDNANCE GEOLOGICAL MAPS OF Cornwall, Devon, AND WEST SOMERSET. Imprint: Standidge & Co. Lith. London. below title.

[1] However, unlike the original series, the maps were never sold as a county set. The individual sheets all have full piano-key borders, numbers (Ea) and the title: Ordnance GEOLOGICAL MAP of DEVON, WITH PARTS OF CORNWALL & SOMERSET, BY Henry T. De la Beche FRS &c. and some have the mapseller’s imprint: Sold by J Gardner Agent for the sale of the Ordnance Surveys, 163 Regent St. London. In addition sheets have Index of Colours and Explanation of Signs. All maps have signature Engraved at the Drawing Room at the Tower by Benj ⁿ. Baker & Assistants and also Scale of Statute Miles (CeOS). Plymouth Library has Sheet XXIII  (Start Bay), Sheet XXIV (Whitsand Bay to Prawle Point) and Sheet XXV (Dartmoor).