William H. Penning, British geologist, was employed on the Geological Survey of Britain from 1867 to 1880, during which time he was engaged mainly in mapping the mesozoic beds of eastern England. In 1876 he published his first book, entitled Field geology, followed in 1880 by Engineering geology.
Penning came to South Africa in 1880 or 1881 for health reasons and practiced as a consulting geologist in the South African Republic (Transvaal). In 1884, in his paper "A sketch of the high-level coalfields of South Africa", published in the Quarterly Journal of the Geological Society (London), he made one of the first attemps to describe part of the succession of rock strata in the northern region of South Africa. He assumed (wrongly) that the coal-bearing strata of Molteno in the Eastern Cape and those of the Transvaal highveld, KwaZulu-Natal, and the Free State were all identical and hence that coal was present over a vast region. He named these coal-bearing beds the High-Veldt Beds and described them as overlying his Klip River Series (now part of the Transvaal Sequence), consisting mainly of the Magaliesberg quartzite beds (a name that he introduced) and dolomite (of which he recognised only the chert inclusions).
Penning also published A guide to the goldfields of South Africa (Pretoria, 1883, 87p, with map) in which he described conditions on the goldfields at Lydenburg, De Kaap, Tati (near present Francistown, Botswana), and Matabeleland (Zimbabwe). Though including little information about the geology of these regions, the book contained interesting information on the gold finds by early prospectors, including Karl Mauch* and Edward Button*. At this time he was still in South Africa, for newspaper articles by him appeared in De Volksstem (Pretoria) on 27 January 1883 (dealing with geological and mining aspects of the De Kaap Valley) and in the Diamond Fields Advertiser (Kimberley) on 9 February 1883 (dealing with the future prospects of the Transvaal and its gold deposits). He appears to have visited South Africa again more than once in later years. During September and October 1885 he negotiated with the Transvaal government the conditions under which he would be prepared to investigate the presence of diamonds and precioous metals in the territory. The next month he furthermore requested to be appointed as state mineralogist, but without success.
Penning's paper "A sketch of the goldfields of Lydenburg and De Kaap, in the Transvaal, South Africa" (Quarterly Journal of the Geological Society, 1885) described the gold-bearing rocks of the De Kaap Valley and the Magaliesberg beds to the west. Just two years after the discovery of gold on he Witwatersrand, in a paper on "The South African gold fields" (Journal of the Society of Arts, 1888) he gave the name Witwatersrand Series (now Witwatersrand Supergroup) to the sedimentary succession, which he estimated to be at least 5200 m thick, that contains the gold-bearing conglomerates. The Witwatersrand Series and the overlying Klip River Series he combined in his Magaliesberg Formation (or System). A paper by him on "Geology and gold mining: On the geology of the Witwatersrand, with reference to gold mining" was published in the Witwatersrand Mining and Metallurgical Review (1890), followed by "A contribution to the geology of the southern Transvaal" (Quarterly Journal of the Geological Society, 1891). In the latter paper he described four sub-divisions of the Witwatersrand beds, which he named the Main-Reef, Bird-Reef, Kimberley and Elsburg Series. Two years later he compiled a memoir, The geology of the southern Transvaal (London, 1893, 37p) to accompany E. Stanford's Map of the Transvaal goldfields (1888). Shortly before his death he published a small book, Gold and diamonds: South African facts and inferences (London, 1901), which included a description of the geological succession west of Vryburg, and a discussion of the underground water supply of the eastern Kalahari.
Penning's contribution to South African archaeology takes the form of two papers read before the (Royal) Anthropological Institute in England. In the first, "Notes on a few stone implements found in South Africa", published in the institute's Journal (1886, pp. 68-70), he argued that stone artefacts found on the surface in South Africa are not necessarily of more recent manufacture than similar artefacts found at depth in the soils of Europe, as South Africa was not covered by Ice Age debris. He also described some quartzite artefacts from Pretoria. The paper elicited a fruitful discussion on the interpretation of prehistoric finds. In his second paper, summarised in "Exhibition of stone implements from South Africa" (Journal, 1898, p. 54) he again described these artefacts, and one other from the Kalahari, found at the bottom of a water hole sunk through more than a meter of calcrete.
Penning was a Fellow of the Geological Society of London. During his first visit to South Africa he was elected a corresponding member of the South African Philosophical Society in September 1881.