South Africa dwarfs South America: about 1,221,609 km² km² against 17,840,000 km² km². At true size South Africa is about 14.6× larger — the whole of South America fits into South Africa roughly 14 times.
The old Mercator map treated both about equally (1.3× vs 1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
South Africa fits 14× into South America.