SIR WILLIAM HUGGINS, K.C.B., O.M. i8i 



prominences, he was hard pressed by other workers who were 

 engaged in the study of the phenomena of the eclipsed sun. 

 In the other, namely the establishment of the possibility of 

 determining, by measurements of position of the highest refine- 

 ment in stellar spectra, the velocity of approach or recession of 

 the body from which the light comes, nothing short of the 

 inextinguishable faith of Huggins could have carried the work 

 through to a triumphant conclusion. It has been well said of him 

 that with an enthusiastic heart he combined a cool head. 



This earlier pioneer work was carried oiit with an equatorially 

 mounted telescope with an aperture of eight inches, judiciously 

 combined with a spectroscope of two small prisms. Only those 

 who have had experience of work even with the more powerful 

 instruments of modern days, built up upon the experience 

 which Huggins had to gain for himself, can appreciate fully 

 the skill and patience and delicacy of hand and eye which 

 enabled him to make these early conquests. Not that the 

 value of his investigation was unrecognised at the time. On 

 the contrary, the Royal Society put at his disposal the Oliveira 

 bequest which had come into their hands for the construction 

 of a large telescope. And so it came about that just at the 

 end of the period in which the limited appliances had been so 

 well utilised and when they began to be inadequate, Huggins 

 was able to improve his instrumental equipment enormously. 

 The dome was enlarged, its diameter being made i8 ft. instead 

 of 12 ft. ; and in place of the 8-in. object-glass he was provided 

 with a 15-in. object-glass of the short focal length !of 15 ft., 

 and also a Cassegrain mirror, of aperture 18 in. and of focal 

 length 1 1 ft. Each of them was mounted in a suitable tube 

 and they were arranged so that either one or the other, according 

 to the needs of the observer, could be attached to the equatorial 

 mounting. The work of construction was carried out by Sir 

 Howard Grubb in 1869-70. It will give some idea of the 

 activity in the new observatory, if a paragraph be devoted to 

 summarising the modes in which the instrumental equipment 

 was utilised for various researches. 



During five years, 1870-75, the achromatic telescope was used 

 in determination of the velocity of stars in the line of sight, 

 by means of visual observations. The spectra of Uranus and 

 Neptune and of various nebulae were studied and some time 

 was given to observations of Coggia's comet. The rotation 



