C.D. Wentzel, son of David Wentzel and his wife Magdalena von Vogel, came to the Cape of Good Hope as a soldier in 1748. On 24 April 1749 he took the oath as surveyor of the Dutch East India Company at the Cape, a position he held until 1759. On 3 January 1751 he married Aurelia Stavorinus, with whom he had five children at the Cape. That same year he compiled a plan of Cape Town, some 90 by 60 cm in size. The original is lost, but a copy drawn by the surveyor J.W. Wernich* is in the Grey Collection of the National Library, Cape Town. Its professional appearance may reflect either Wentzel's original work or Wernich's copying. The plan was the first proper map of the town of which the compiler is known. It is of particular historical value as it indicates the letter codes of town blocks, allocated from 1695 onwards, that are often referred to in deeds of transfer and other official documents.
In 1752 Wentzel accompanied the expedition into the Eastern Cape led by Ensign A.F. Beutler*, as surveyor and cartograher. They travelled via Caledon and Swellendam to Mossel Bay, crossed the Outeniqua Mountains at Attaquaskloof, and went along the Langkloof to reach St. Francis Bay early in May. After crossing the Bushmans River and the Fish River they travelled further from the coast, reaching the Keiskamma River near Line Drift on 5 June. Proceeding across the Kei River they reached the vicinity of present day Butterworth before turning back on 10 July. Returning first along their old route they turned westwards to where Bedford now is and explored the valley of the Fish River to the vicinity of present day Cradock, before turning south to where they had crossed the Bushman's River. They returned to Cape Town via their outward route, reaching it on 6 November.
Wentzel compiled a map of the route followed, based mainly on a compass traverse. Daily observations of the sun were supposed to have been made to determine latitude, but the errors on the map suggest that such observations were not used. The map measures about 1.0 by 2.7 meters (scale c. 1:350 000). Longitudes are indicated east of the peak of Teneriffe (with Cape Town at 38? E) and distances measured in miles of 1900 Rhenish roods (7.158 km). On the back the map is identified as Caart van het Zuydelijk deel van Africa - dienende by 't Journaal van een landtogt op ordr van den Gouverneur Tullbagh, gedaan door den Vaandrig Beutler in 1752, in deze ordre opgenomen door C.D. Wentzel, Landm. (Map of the southern part of Africa - forming part of the Journal of a land expedition ordered by Governor Tulbagh, carried out by Ensign Beutler in 1752, drawn up by C.D. Wentzel, surveyor). It was later included in the map collection brought together by Governor C.J. van de Graaff*. At least four copies of the original survive. These are in the Cape Archives, the Africana Museum in Johannesburg, and in the Dutch archives in Den Haag and Delft. The existence of several smaller contemporary copies indicate its popularity. As a result of the accumulation of errors during the traverse, and Wentzel's tendency to conform to erroneous existing maps of the coast, his geographical coordinates are inaccurate. None the less it is a remarkable achievement and has been described as "one of the earliest and generally trustworthy sources of information" on the Eastern Cape (Board, 2003, p. 121). It shows the expedition's route in relation to geographical features such as mountains and rivers, as well as tribal territories, covering a strip of territory extending over 900 km along the southern Cape coast.
Five less important maps by Wentzel survive in the Dutch archives. Two of these depict Cape Town and its fortifications, the others are a crude outline of the Cape Peninsula and False Bay, a plan of two gun batteries at Simon's Town, and a plan of a group of five farms. He surveyed and drew diagrams of 122 properties between 1748 and 1759 (Cape of Good Hope, 1859). He was sent back to Europe in 1760, but in 1766 returned to the Cape as an engineer-lieutenant and remained until his death ten years later.