Captain Joshua Slocum embarked, in June 1898, on a trip around the world, with a crew of one (that is, all by himself), and he was soon to become the first person to succeed in that quest. His book, appropriately titled Sailing Alone Around the World, became a bestseller in 1900, and is still in print, from Dover Books.
When he arrived in Pretoria, “I met [Paul] Kruger, the Transvaal [South African] president. His Excellency received me cordially enough; but my friend Judge Beyers, the gentleman who presented me, by mentioning that I was on a voyage around the world, unwittingly gave great offense to the venerable statesman, which we both regretted deeply. Mr. Kruger corrected the judge rather sharply, reminding him that the world is flat. ‘You don’t mean round the world,” said the president; ‘it is impossible! You mean in the world. Impossible!’ he said, ‘impossible!’ and not another word did he utter either to the judge or to me. The judge looked at me and I looked at the judge, who should have known his ground, so to speak, and Mr. Kruger glowered at us both. My friend the judge seemed embarrassed, but I was delighted; the incident pleased me more than anything else that could have happened. It was a nugget out of Oom Paul, some of whose sayings are famous…. Only unthinking people call President Kruger dull.”
A political leader denying science would not be shocking today, of course, but back then it made some waves. This made it into a political cartoon, as such things sometimes do.