Green’s Dictionary of Slang

whisky or rough, strong brandy distilled in South Africa.

1863		L.D. Gordon Feb. Letters from the Cape (1875) 290: The English drink [...] ‘Cape smoke’ (brandy, like vitriol).
1876		F. Boyle Savage Life 193: Our fellows want it hot and strong like ‘Cape Smoke’.
1878		press cutting in Ware (1909) 63/2: Mr Cecil Ashley strongly insists on the terrible effects of the ‘Cape Smoke’. At present this evil vapour may be bought at sevenpence a bottle, and traders wander about the country with waggon loads of it, which they almost force on the natives.
1884		Sporting Times 20 Sept. 7/2: Drink plentiful [...] ‘Congo,’ ‘Cape Smoke,’ ‘Chained Lightning,’ ‘Boer Brandy’.
1889		H.A. Bryden Kloof and Karroo 222: We adjourned [...] to Mr. Evans’s sanctum, to indulge in pipes and a glass of ‘Cape smoke’.
1892		B. Mitford ’Tween Snow and Fire 222: ‘That’s McDonald’s ‘Cape Smoke,’ laughed the police sergeant.
1894		Truth (Sydney) 29 Apr. 1/7: A half-empty bottle of Cape smoke [was] in a bundle under her head.
1904		Sydney Sportsman (Surry Hills, NSW) 17 Feb. 3/6: Capetown, with Cape smoke (Anglice peach brandy) at 6d per bottle,is evidently not a safe place.
1909		J. Ware Passing Eng. of the Victorian Era.
1916		‘Anzac’ On the Anzac Trail 77: [W]hisky that takes the lining of your throat down with it [...] a soothing liquid that licks ‘forty-rod,’ ‘chained lightning,’ or ‘Cape smoke’ to the back of creation.
1937		C.R. Prance Tante Rebella and her Friends (1951) 28: ‘Heather Mixture’ [...] is even stronger than our ‘Cape Smoke’.
1988		(con. WWII) J. Robinson Jack and Jamie Go to War 133: Holy cow! [...] I could use some of that Cape Smoke right now.