RECORDING THE FACTS: HENRY DE LA BECHE’S MAPS AS DATA REPOSITORIES

As a young man, Henry Thomas De la Beche (1796-1855) entered the elite circles of gentlemen geologists. In 1822, he geologically mapped south Pembrokeshire, Wales, using the Ordnance maps (1:63,360). It was the South Pembrokeshire map that marked the beginning of “that system of geological illustration which . . . [De la Beche] subsequently perfected in the maps of the Ordnance Geological Survey” (Hamilton 1855).

De la Beche’s mapping activities continued with Jamaica in 1824 (and he is considered the Father of Jamaican Geology) and Devon’s Tor and Babbacombe bays in 1827. De la Beche advocated the accurate portrayal of facts in graphic form—including the avoidance of vertical exaggeration in cross section—so that viewers in the future could retrieve the unadulterated data.

In 1830 De la Beche returned to south Devonshire to more completely record the geology on the Ordnance sheets. When his personal finances deteriorated in 1832, De la Beche petitioned the government to be paid to geologically color eight Ordnance sheets that would be of “great practical utility.” He was then able to leverage this completed project and extend geological mapping to other parts of the country. In 1835, he became the first Director General of what would become the British Geological Survey. In this position, De la Beche supervised the rapid production of maps that were equal or superior to those of other countries (Flett 1937). As he supervised more surveyors, he sought consistency of results through education of his directors. The geological mapping was to be completed through rigorous field observations and precise recording of facts, “by which systematic investigations and uniformity of results may be secured” (De la Beche 1845). Many who learned geological survey work under De la Beche brought his methods to other countries, including Australia, Canada, Ireland, India, and the United States of America. De la Beche’s geological maps serve as graphic data repositories of facts recorded during their construction, while his surveying techniques have enduring influence.