262 Annwersary Address by Sir A. Geikie. —[Nov. 30, 
now so appropriate for such purposes had been evolved or even thought of, 
showed his close application and the exquisite refinement of his appliances. 
In rapid succession he informed us of the similarities in constitution between 
some types among the fixed stars and our own Sun, and of the marked 
differences shown by other types, thus leading on to the great fundamental 
subject of the classification of the stars and initiating the discussion of the 
order of their evolution. The early application of photography to the spectra 
of objects whose light is so feeble demanded wonderful patience and skill: it 
was rewarded with an immediate crowd of physical results in the registration 
of spectra far beyond the visible limit in the violet, among which the 
recognition of the second spectrum of hydrogen may be recalled. So, too, at 
a later time, when the four lines of the ordinary spectrum of this gas were 
shown by Balmer to belong to a very definite algebraic series, which ought to 
include numbers of other lines whereof laboratory experiments showed no 
trace, it was Huggins who called in the aid of the celestial laboratory of the 
stars and pointed to the exact succession of the missing lines in the spectra of 
certain stars—thereby infusing new zeal into the efforts of theorists to unravel 
the secret of the origin of the spectrum. 
When the same refined appliances were turned to the scrutiny of the 
nebule, which are spread over such vast regions of the sky, the news soon 
came that the problem raised by William Herschel and his successors had 
now been definitely solved by the discovery that these nebule were not all 
clusters of stars, but that some of them shone as masses of glowing gas. In 
solar work reference may be made to Huggins’ proposal to render the flame- 
prominences visible in open day by great optical dispersion, and also, though 
the result was less satisfactory, to his persistent attempts to photograph the 
solar corona by aid of coloured screens. But perhaps the most brilliant 
of his achievements was his early conception, undeterred by full knowledge 
of the difficulties which had to be faced, that it might be possible to measure 
the velocities of approach or recession of the stars by spectroscopic means. 
In a masterly investigation he proved to the world that his expectation was 
well grounded, and that the development of instruments specially adapted 
for this new outlook into astronomy demanded vigorous prosecution. His 
other laboratory work, all designed for the elucidation of astronomical 
problems, can only be referred to, such, for instance, as his research into the 
nature of the luminosity of radium salts. 
Sir William Huggins was elected into the Royal Society as far back as 
1865. During his long association with us he took the keenest interest in 
the affairs and the success of the Society. He was repeatedly elected into 
the Council, where his total length of service amounted to no less than sixteen 
