Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 1-16

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 17-19

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 21-25

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 27-32

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 41-44

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 45-49

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 51-53

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 55-57

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 59-71

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 73-86

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 87-89

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 91-93

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 107-110

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 111-115

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 121-123

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 125-136

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 137-143

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 145-147

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 149-152

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 153-167

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 169-171

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 173-178

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 225-228

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 229-233

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 283-292

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 293-296

Published in Transactions of the Royal Society of South Africa, in 1919, in volume 8, issue 1, pages 303-311