S.S. Tartar - 1883 - Steamship History and Information
THE Union Steamship Company's Royal Mail steamship Tartar, which arrived at Southampton at 4.15 A. M. on Sunday, July 28th, made a very rapid passage from Cape Town. She left that port at 5.43 P. M. on July loth, and the distance run-5,986 miles, via Madeira—was accomplished in 17 days, 10 hours, 32 minutes, gross time, the net steaming time being 17 days, 6 hours, 11 minutes, giving an average speed over the whole distance of 14.5 knots per hour.
Source: Ocean: Magazine of Travel, Vol. III, No. 2, September 1889, Page 43