S. P. Langley— Observations on Mount Etna. 35 
vation of about 4,200 feet, on the southeast slope of the moun- 
tain. It is in lat. 37° 88’ 55’"5 N. and long. 6" 08™ 11°5 east 
of Washington.* 
After a preliminary visit, I ascended the mountain on Dee. 
25th, 1878 (Christmas day), leaving Catania in the morning, and 
reaching the “Casa” after dark. I had no aid or assistant, but 
was accompanied by a native guide and by soldiers (Cara- 
binieri) sent by the Prefect of Catania, all of whom remained 
ith me. These soldiers were sent on the application of the 
Honorable Mr. Marsh, Minister of the United States at Rome, 
who kindly and effectually interested himself to procure me 
official introductions from the Italian ministry to the Prefect of 
Catania, and I was obliged in this as in other instances, by every 
attention which our own consular officers or the Sicilian author- 
ities could render. 
y instruments consisted of a telescope of 84 inches aper- 
ture, mounted equatorially (but without circles), and resting 
upon a tripod stand. It is the property of the United States 
Naval Observatory, and for its loan I am specially indebted to 
the kindness of Admiral John Rodgers, the Superintendent. 
With this was a spectroscope, belonging to the Allegheny 
Observatory, provided with a Rutherfurd speculum metal grat- 
ing of 17,296 lines to the inch, and with collimating and observ- 
ing telescopes of 1*1 inch aperture and 14 inches focal length. 
T had no chronometer, nor any means for observations of pre- 
cision. 
‘ re am indebted for these determinations to the kindness of Professor ©. H. F, 
eters, 
