I am much indebted to my sister, Miss Orr, who has helped me in preparing these sheets for the press. The index is mainly her work.
Thanks are also due to several members of the staff of this observatory: Mr. Sitarama Aiyar made some calculations, Mr. Nagarajan Aiyar projected the [map facing page 295], Mr. Krishna Aiyar prepared photographs of several illustrations, and Mr. Krishnasawmy typed the greater part of the copy for press. Mr. Raymond Beazley, the Trustees of the British Museum, and Messrs Macmillan, have kindly allowed me to reproduce illustrations from their publications.
To all these I offer grateful thanks.
M. A. EVERSHED.
Kodaikanal Observatory,
South India.
October 1913.