Ernest H.L. Schwarz, geologist and geographer, studied at the Royal College of Science, London, where he was an outstanding student and was made an associate of the college (ARCS). He continued his studies at the School of Mines at Camborne, Cornwall, but did not obtain a university degree. In 1895 he came to South Africa and that same year presented fossils from England and Germany to the South African Museum. He settled in Johannesburg and later that year became the (anonymous) editor (or one of the editors) of a new journal aimed at improving the public's understanding of science, The Scientific African, published monthly in Cape Town and distributed all over South Africa. The journal was the first of its kind in southern Africa and represented a major attempt to educate the public in the methods and results of scientific enquiry through short articles, news items, sketches of local scientists, etc. Schwarz contributed, among others, articles on A.G. Bain* and South African coal. However, only five issues of the journal were published (November 1895 - March 1896), after which it was discontinued.
In 1896 Schwarz was appointed as a field geologist to the recently established Geological Commission of the Cape of Good Hope, directed by G.S. Corstorphine*. He spent the next ten years doing geological surveys of various regions, particularly in the south-western part of the Cape Colony, often in collaboration with A.W. Rogers*. The two men differed in their approach, Rogers being a cautious scientist while Schwarz was more attracted to the speculative side of geology, but despite several threatened breakups they managed to continue working together and wrote many joint reports. Most of these, and others by Schwarz alone, were published in the Annual Reports of the Geological Comission for 1896 to 1905. He became known for his investigations of the older rocks of the Cape Colony and, with Rogers, their correlation with those of the Transvaal; for his descriptions of the complex folds of the Bokkeveld Group, the glacial horizons of the Table Mountain Sandstone, the major faults of the southern Cape, the Alexandria Formation (which he named), and the geological history of Baviaanskloof. The latter formed the subject of an excellent paper, "Baviaan's Kloof: A contribution to the theory of mountain folds", which he delivered at the joint meeting of the British and South African Associations for the Advancement of Science in 1905. It was included in the Addresses and papers... (Vol. 2) published after the meeting. On 20 April 1904 Schwarz married Daisy M. Browne, but they had no children. In May the next year he was appointed as the first professor of geology at Rhodes University College, Grahamstown, a position he held to his death in 1928, and simultaneously as keeper of geology and mineralogy at the Albany Museum. At the museum he arranged collections to illustrate South African stratigraphy and mineralogy, as well as general paleontology and mineralogy. When the Union of South Africa was formed in 1910 John Hewitt* became the first full-time director of the museum and Schwarz had to choose between his two posts. He chose to remain at Rhodes, though he continued to assist the museum in an honorary capacity and later became a member of its board. At Rhodes few students initially took geology for its own sake and later he lectured also in geography. He was the only member of staff in the geology department until 1927 and in later years had a heavy teaching load. However, his main interest was in his own research and writing, leading to well over a hundred publications during his career. These included two geological books, Causal geology (London, 1910), which was largely a speculative application of T.C. Chamberlin's planetesimal hypothesis to some general problems of stratigraphy, and South African geology (London, 1912), as well as a geography textbook, A South-African geography (London, 1921).
Schwarz was elected a Fellow of the Geological Society of London before he settled in Grahamstown. He became a member of the South African Philosophical Society in 1895 and when it became the Royal Society of South Africa in 1908 was elected a Fellow of the latter. Most of the papers that he contributed to the society's Transactions were published during a brief period just before he left Cape Town, for example, "The volcanoes of Griqualand East" (1903), "High-level gravels of the Cape and the problem of the Karroo gold" (1904), and "The rocks of Tristan da Cunha" (1905). In the latter paper he speculated that a Devonian continent had occupied the southerm Atlantic Ocean. In 1905 he became a member also of the Geological Society of South Africa. Some of his papers published in that society's Transactions dealt with "The Transvaal System in Prieska, Cape Colony" (1905), "The Alexandria Formation (Upper Cretaceous) on the south coast of Africa" (1909), and "Contribution to the aquaeo-igneous solution theory of rock magmas" (1912). He joined the South African Association for the Advancement of Science in 1903, shortly after its formation, and at the annual congress held at Grahamstown in 1908 was president of Section B (which included geology). His presidential address, "The discoveries of economic importance made by the Albany pioneers", dealt with the contributions of the 1820 settlers to the discovery of minerals in the Cape Colony, and with the life and work of Dr W.G. Atherstone*. During the next seven years he regularly contributed geological papers to the annual Report of the South African Association for the Advancement of Science and its successor, the South African Journal of Science, as well as to British and American geology journals. Other papers by him were published in the Records of the Albany Museum. For example, in "South African Palaeozoic fossils" (1906) he gave the earliest descriptions and illustrations of megaplants from the Cape Supergroup, including several new taxa, though he had not collected any of these himself.
Schwarz is probably best remembered for his proposed Kalahari irrigation scheme, which attracted widespread interest because it promised huge benefits to a drought-ridden country. Following his study of the ancient drainage patterns of Africa, and acknowledging an earlier Kalahari irrigation scheme advocated by Ferdinand Gessert*, he conceived the idea of restoring an ancient drainage system in the Kalahari. He first explained his scheme in The Star of 31 January 1918. Next came his comprehensive paper, "The dessication of Africa: The cause and the remedy", read at the annual meeting of the South African Association for the Advancement of Science in July that year and published in the association's Report for 1918. Many other scientific and popular publications followed. An expanded and modified scheme was published in his book The Kalahari; or, thirstland redemption(Cape Town, 1920). He pointed out that large permanent lakes had existed at Etosha Pan, the Makgadikgadi Pans and Lake Ngami in past eras and claimed that these had dried up only during the last few centuries when their catchment areas began to be drained by the Kunene, Chobe and Zambesi Rivers. The loss of these bodies of open water, he claimed, caused a decrease in rainfall over the Kalahari basin from about 1860 onwards. Restore those lakes, he said, and the progressive aridification of southern Africa will stop. To achieve this he proposed dams in the Kunene River and in the Chobe River just above its junction with the Zambesi, to divert water through currently dry river beds into the Makgadikgadi Pans. The resulting lake of some 40 000 square kilometers he thought would increase rainfall over a large part of southern Africa by up to 250 mm per year. Farming prospects would improve, while some of the water could also be used for irrigation along river valleys south of the lake down to the lower Molopo River.
His proposals led to a flood of scientific and popular literature. In broad terms, the general public supported the scheme enthusiastically and admired Schwarz for his breadth of vision. However, most scientists questioned the geographical assumptions on which it was based and thought that the benefits were grossly overestimated. In 1925 the South African Department of Irrigation sent an expedition led by the eminent geologist Dr Alexander L. du Toit* to investigate. The expedition visited the northern Kalahari from June to October that year to collect data pertaining to the eastern part of the proposed scheme and a number of alternative proposals. In the resulting report du Toit pointed out that many assumptions made by Schwarz with regard to declining rainfall, the recent disappearance of large lakes in the Kalahari, the climatic consequences of the scheme, the amount of water carried by the Chobe and other rivers, ground elevations, dry river courses and other geographical features, and the cost of the scheme, were either wrong or could not be supported by available data. The scheme was rejected as unworkable. However, Schwarz continued to promote his ideas and after his death his wife wrote further articles in support of his scheme.
Schwarz accompanied Du Toit's expedition for some time and remained in the northern Kalahari to study the region and its inhabitants. His visit led to a paper on "The northern Kalahari" (South African Geographical Journal, 1926) and a book, The Kalahari and its native races (London, 1928), in which he expressed daringly unconventional views on the people of the region.
From 1900 to 1903 Schwarz was an examiner in geology for the University of the Cape of Good Hope, and in 1923 he was president of the South African Geographical Society. However, he had several interests outside geology and geography. Perhaps inspired by the return of Halley's comet in 1910 he set up a 250 mm reflecting telescope that belonged to Rhodes University College at his house and invited his students to examine the moon and planets. Later he published a paper on "The geographical features of the moon" in the South African Geographical Journal (1923). In 1901 he described rock paintings and a "Bushman pot" from a shelter overlooking a tributary of the Riet River, Western Cape, in a paper before the South African Philosophical Society. One of the papers he read before the South African Association for the Advancement of Science dealt with "The circle in South African myth" (1907). During his early years at Rhodes he wrote a novel set in a South African Karoo village, Brendavale: A narrative (London, 1908), using the pseudonym Ernest Black.
Schwarz was a tall, gentle and introspective man who found it difficult to accept disappointments. He was always full of ideas and explanatary hypotheses, and though these were not always fully worked out his suggestions were usually of value. He was inclined to draw quick conclusions, and his interests were wide, rather than intensive. In 1927 he visited Senegal on six month's leave to study, among others, the upper drainage area of the Niger River. As there was insufficient time to complete the work he returned the following year, but died in St Louis of a heart attack. After his death a letter to the editor of the Geographical Journal was found on his table, in which he advanced a solution to the problem of the route followed by Hanno the Carthaginian along the Senegal coast.