And ...

Paul Hoefler
A much harder beast to domesticate

Between 1900 and 1950, the elephant training station in the Belgian Congo evidently succeeded in training about one hundred African elephants, which were used for transportation and to clear vegetation. The tradition continues: a few trained elephants and elephant trainers can still be found at the African Elephant Domestication Center at Gangala-na-Bodio, near Garamba National Park in the Democratic Republic of the Congo. Elephants from the Center are used to carry tourists on game-viewing safaris. American filmmaker Paul Hoefler visited the elephant training station in the Belgian Congo and described it in his book, Africa Speaks: A Story of Adventure (The Chronicle of the first Trans-African Journey by Motor Truck from Mombasa on the Indian Ocean to Lagos on the Atlantic, through Central Equatorial Africa) (Philadelphia: John Winston Company, 1931):

For many years the Belgian government has maintained a training station for elephants at Wanda [, Belgian Congo]. From the wild herds that roam in the surrounding forests, they capture young animals and these are brought to the post for a course in discipline. They are then sold to plantations or to the missions. The African animal is quite different from the Indian species, a much harder beast to domesticate, never becoming entirely docile. Until the Belgians undertook this work, it was thought impossible to train the African elephant. They have succeeded to a certain extent, but the results obtained are small considering the amount effort and time expended, and it is not likely that this animal will ever become a great aid to mankind, comparable to his Indian cousin.
[Heart of the Congo]