PHILOSOPHICAL TRANSACTIONS 
OF THE 
ROYAL SOCIETY OE LONDON 
Series A, YOL. 206, pp. 403-452. 
[Plate 9.] 
DETERMINATIONS OF WAVE-LENGTH FROM 
SPECTRA OBTAINED AT THE TOTAL SOLAR ECLIPSES OF 
1900, 1901 AND 1905 
BY 
F. W. DYSON, M.A., F.R.S., 
ASTRONOMER ROYAL FOR SCOTLAND, PROFESSOR OF ASTRONOMY IN THE UNIVERSITY OF EDINBURGH 
(member of the expeditions from the royal observatory, Greenwich). 
LONDON: 
PUBLISHED FOR THE ROYAL SOCIETY 
BY DULATJ AND CO., 37, SOHO SQUARE, W. 
CONTINENTAL AGENTS, MESSRS. ERIEDLANDER AND SON, BERLIN. 
1906. 
A 409. 
Price Two Shillings and Sixpence. 
23.8.06 
