Whilst studying at the University of Kansas Brown volunteered with the National Museum of Natural History and took part in collecting expeditions in the US.

While employed by the Smithsonian Institution he took part in an expedition to the Belgian Congo to observe the Solar eclipse of December 22, 1889.

[3] Brown majored in natural history, receiving a bachelor of science degree, and studied under Professors Francis H. Snow and Lewis Lindsay Dyche.

[2] Brown later collected, with Dyche, specimens from Las Vegas, New Mexico, including two bison that came to be the centerpiece of the museum of the University of Kansas.

An arrangement with expedition leader Professor David Peck Todd allowed Brown to accompany the party to collect natural history samples for the National Museum.

[6][7] The expedition sailed on October 16, 1889, aboard the USS Pensacola, stopping at the Azores en-route where Brown, assisted by officers and men from the ship, collected samples of fish and seashells.

[7] Brown accompanied the expedition to the Congo via Freetown, Sierra Leone; Elmina, Ghana; Angola (including Luanda and the Cuanza River), Cape Town (South Africa), St Helena and Ascension Island.

[12][2] Brown fought in the First Matabele War of 1893-94 and in return for his service was granted 13,000 acres (5,300 ha) of land in what became Rhodesia.