Johannes Schumacher came to the Cape of Good Hope from the Netherlands as a soldier in 1770. At the Cape his name was recorded as Johan Schoe(n)maker by the Dutch. He served in the company commanded by Major H. Prehn*, but in 1778 was transferred to the company under the command of Captain (later Colonel) R.J. Gordon*. From 1882 to 1889 he was an assistant in the armory.
Schumacher was an artist whose numerous acurate scenic drawings included many that recorded scenes in the interior of the country for the first time. In September-December 1776 he accompanied Hendrik Swellengrebel, son of the Governor of the same name, on a journey to the Eastern Cape. Though he was not identified by name in Swellengrebel's journal, his signature appears on two of the drawings associated with it. Altogether 66 of his aquarelles are preserved as part of the Swellengrebel family records at Breda, the Netherlands. A few of these are views of Cape Town and environment, but the majority form a pictorial record of Swellengrebel's journey. Most of these were reproduced in an album by Hallema (1951). The viewpoints of many were identified by V.S. Forbes.
Schumacher is credited with having made the first known reproduction of Cape rock art during this journey. (A.F. Beutler* mentioned having seen many rock paintings along the Fish River in 1752, but made no copies). The Swellengrebel collection contains a single drawing depicting rock art (not published by Hallema, 1951), a photograph of which was described by Macfarlane (1954). It shows 25 solid black figures, including four humans with raised arms, four ostriches and various antelopes, all facing in the same direction. According to Swellengrebel's journal (quoted by Hallema, 1951, p. 19) the drawing was made on 14 October 1776 on the farm of D. van der Merwe. A Hottentot or Bushman there said that near his place the rocks were painted with all sorts of animals. Swellengrebel asked him to draw the animals with ink on paper and remarked that one had to put the name beneath each figure to know what it represents. It seems therefore as if the figures were not copied from the rock by Schumacher, but were drawn from memory by one of the local inhabitants, after which a member of the expedition wrote the names below the figures.
During 1777-1786 Schumacher accompanied Gordon on his four main journeys into the interior: Gordon identified him in his journals as "Schoemaker de schilder" (Schumacher the painter) and the large difference in social standing between them precluded a meaningful personal relationship. Schumacher was furthermore not as robust and fearless as Gordon and hence did not earn the latter's respect. Judging from Gordon's journal he also had little interest in exploration or natural history and merely accompanied the expeditions because he had been ordered to do so. He must have been responsible for a number of drawings in the extensive Gordon Collection, preserved in the Rijksmuseum, Amsterdam, but it is not always clear which drawings were made by him and which by Gordon (the latter personally copied some rock paintings in the upper Zeekoei Valley in November 1777). Schumacher has been credited with drawings of some of the more conspicuous tortoises, lizards and vipers (Bauer, 2003). His topographical drawings have been characterised as accurate but rather na?ve.