74 Scientific Intelligence. 
northernmost limit of the eee ra sa limit which 
it has already well nigh reached. It travels by means of wings, 
But “it undoubtedly availed itself se no ee EEN extent, of 
8. Bulletin of the Daeg Commission—U. 8. 
Geol. and Geogr. ove. — 2 pp. and No. 2, 14 pp. 8vo.— 
The Entomological Commission consists of 
Packarp, Jr., and Cy Their first bulletin treats of 
and No. 2 of their natural history and habits in the young 
unfledged state, with wood-cuts, and a map of the region east of 
the Rocky Mountains overran by the insect. 
IV. AsrRonomy. 
. Astronomical and eioteoroligieat Observations made during 
ee year 1874 at the U. S. N. Observatory, Rear-Admiral Davis, 
upt. Washington, 1877. —This alin contains the observa- 
— of the year 1874 atthe Naval Observatory, with the reduced 
sults. The astronomical work has been mostly done by means 
of the three instruments, the transit circle, the 26-inch equatorial, 
ral circle. The latter instrument has been under the 
of the U. S. N. Observatory (see p. 242, vol. xiii, of this Journal), 
illustrated with heliotypes of the eemeneds ; IL. Report on the 
difference of longitude between Washington and Ogden, Ce 
y, Professor Eastman, This difference is found to pes 
te Relative ages of the Sun and certain fixed Stars. _proteanor 
Kirkwoop closes a communication upon this subject to the Amer- 
ican  ploeophipsl Society with the following summary of his 
conclusion 
tt. The history of ibe hg system is comprised within twenty _ 
or thirty millions of 
-<) rom the fact that: the larger component of guehe Centauri 
ice as much light as the sun while the mass of the 
our solar system is the more advanced in its Shien! history. 
(3.) 61 Cygni seems to have reached a greater degree of con- 
densation than the sun, since, on the hypothesis of equal density, 
the surface of the larger member is ae that of the sun, 
while the intrinsic > light | is less than on 
e companion of Sirius soca to have reached a stage 
of greater maturity than the sun, while the contrary seems to be 
true in regard to the spat, star, H, As N, 
