During the summer of 1905 I had the good fortune, as one of the foreign guests, to accompany the party of the British Association for the Advancement of Science on a visit to the colonies of South Africa. The chief dates of the journey were as follows: Having left New York on July 15, I sailed from Southampton on the steamer Saxon with the third detachment of the Association party on July 29, and reached Cape Town on August 15. Meetings were held there for three days. On August 19 I set out by rail (see figure 1) with a party of geologists for the interior, spent four days in the Karroo, and then hurried across country via Johannesburg to join another geological party in the Vryheit district of Natal. Returning to Johannesburg, meetings were resumed from August 29 to 31, and then a third geological excursion . . .