S. P. Langley— Observations on Mount Hina. 41 
observed in using the same test on Pike’s Peak, or from the sum- 
mit of the Lae of Gizeh. The transparency of the air is 
nevertheless such as is very rarely seen in the Eastern United 
States; but all this while, the Tone continues very bad— 
almost as bad as I ever saw it an ywhere. 
ecember 29th, 1878. Morning and calm with light 
cirrus clouds. Examined sun with re power (70). Definition 
only rye f yet caught glimpses of “ rice-grain” structure, such 
as could not have been seen at Allegheny under like definition 
e. the ackieeia transparency which would almost never be found 
ansocited with even ordinary definition at home here told in 
av 
December 31st, 1878. The sky of as aie ainag a blue as T 
have seen, and optically tranquil. The so-called “ rice-grain” 
structure of the solar surface is beautifully donned with the high- 
est telescopic power (212), and this is the best evidence of the pos- 
sibilities of vision ye as I have never before seen such defini- 
tion upon the s anywhere, and pee of all under a blue sky. 
ith the spectroscope using the small cha y sep grating, work 
is difficult, owing to the absence of clockwork and the presence of 
wind, Yet under Mess disadvantages, D, can he used for view- 
ing the forms of two adjacent protuberances, nearly as well as C, 
1474 Kirchhoff is reversed, occasionally shining out nearly as 
sr ge as the “Helium” line, while }, is repeatedly seen bright 
occasions at Allegheny. I much regret not having a cyanometer 
but sae that this, an ordinary blue here, is deeper and purer 
Biante ny but the very best, of the skies of the Eastern United 
tate 
tela oe ef the E lines is made* 1474 K is doubled, and eight 
I remained upon my Bisied’ sadion said the 14th of Janu- 
ary, at which time the snow line had descended to some dis- 
tance below me, and the weather became so bad that there was 
no prospect of adding materially to the results already obtained. 
During my brief stay in Europe I had the pleasure of meet- 
ing .several distinguished continental observers, and learned 
* Not reduced here. 
