As a result of a broad education, he learned to speak fluently in German and French, and acquired a basic understanding of Italian and Spanish.

[1] A year before Elkin left Strassburg, he had a meeting with the directory of the Cape Observatory, David Gill.

While at the observatory, Gill and Elkin collaborated to measure stellar parallaxes of first magnitude stars using a heliometer.

Working with Frederick L. Chase and Mason Smith, the heliometer was used to undertake a survey which identified 238 parallaxes.

[3][4] Using two groups of cameras with rotating shutters, an idea first suggested by Jonathan Homer Lane, he was the first to accurately determine meteor velocities.