IX.—The Solar Spectrum in 1877-1878, with some practical idea of its 
probable temperature of Origination. By Piazzt Smyru, F.R.S.E., and 
Astronomer Royal for Scotland. (Plate II.). 
CONTENTS. 
PAGE 
Part I.—Of the instruments employed and the range of Spectrum observed. . 2 : . 285-287 
II.—Of a temperature deduction touching the photospheric surface of the Sun, . : . 287-291 
III.—The whole Solar Spectrum observations, : ‘ j . : : . 291-336 
IV.—Accompanying Meteorological Journal, , : ; t ; ; Bil) 
V.—Numerical steps in Spectroscopy according to temperature, . 338-340 
APPENDIX.—Professor 8. P. Lan@ieEy’s recent American observations on the oer of the Sun’: 8 
photospheric surface, : : - : : : : : : 341-342 
Part I. 
Although the Spectrum whose linear record is now presented to the Royal 
Society, Edinburgh, is unfortunately not so perfect as it might have been with 
better apparatus (but which I did not possess)—yet it represents the labour 
and expense connected with two voyages in 1877-1878 to Portugal ; and many 
weeks work there in both years, with the sun in a more favourable position for 
observing really solar, and not telluric, or atmospheric, phenomena, than is 
ever, at any time, obtainable in Great Britain.* 
In fact, it purports to be a spectrum of the sun at an average altitude of 
about 70°, with everything from the ultra red, to the ultra violet, end,— 
so far as that is amenable to the human eye and glass transmission in an 
experimental apparatus ;t where prism trains of dispersions from 10° to 50° 
(between A and H), were employed ; magnifying powers from 10 to 20; aper- 
* I should here most thankfully acknowledge, seeing that the work was thereby so greatly 
facilitated, the extremely liberal and generous conduct of the Pacific Steam Navigation Co. of Liverpool ; 
who, four times over, kindly and safely conveyed all the large packages of scientific instruments, free 
of expense, in one or another of their several magnificent steam-ships of 4000 tons burthen. These 
fine vessels start every month on their grandly oceanic voyages to South America via the Straits of 
Magellaen, taking Lisbon in their way; and form an almost luxurious, at the same time that they are 
both a speedy and yet admirably economical, method of passing and repassing between cloudy Britain, 
and its favourite little, historic Ally in the clear and sunny South. 
Among those to whom my thanks are more particularly due, I trust to be excused for mentioning 
Captain Haminron of the Aconcagua, Captain Graves of the Cotopaxi, Chief Officer Frrmnp of the 
Liguria, Captain Hays of the Valparaiso ; and though last, by no means least, Mr SanpErson, the 
courteous Secretary of the Company, and Reainatp Harrison, Esq., the active and ever watchful 
Medical Officer of Liverpool’s most extensive and busy Port. 
+ Though the apparatus was put together at home, the several important parts of it were furnished 
by, and are altogether due to, the professional skill of M. Satiuron, 24 Rue Pavée au Marais, Paris ; and 
Mr Apam Hitcer, 192 Tottenham Court Road, London. 
VO, XXIX. PART I. 4D 
