Astronomy. 407 
same period, but not uniformly ; increasing for ten days, then re- 
maining stationary for a like period, after which there was again 
an increase for ten days, followed by a second stationary period ; 
these changes being unaccompanied by any marked variation in 
i d orr 
n 
nucleus, which could not, Signor Schiaparelli considers, have ex- 
ceeded 350 miles in diameter when nearest to us, from which he 
rete oe its density must then have been considerable, as it 
alone ned the materials for the coma and tail in all succeed- 
ing dpparitions of this comet. The appearance of the luminous 
jets is then discussed, and is connected with a general want of 
symmetry in the head of the comet, the left side of which (suppos- 
ing the tail to be below the head) was more developed, so that the 
comet resembled a stick with a knob on one a The Hees re- 
the xyes of the orbit on August 10. The lateral deviation of the 
tail, which was very considerable, Prof. Schiaparelli refers to an 
explosive force from the left of the nucleus, from the effect of 
which the particles projected from the head would, under the ac- 
tion of a repulsive force from the sun, describe parabolas, having 
the head as vertex and the radius vector as axis, the tail being 
curved back va: near its extremity, it became parallel to the radius 
t 
vector. This uld — the nucleus (which was apparently 
sineyraitnétriodl) ans rve a nearly constant — in space, 
which the author candies stir ab result either fr ) 
prolongation of shé- ra ada: ecko the axis of the parabolas which 
would be described by the particles of the tail if only under the 
mie repulsive practises Notices, February, 1875. 
cil’ have awarded chs old — to Prof. D’Arrest, for his wae 
entitled * Siderum Nebulosorum Observationes Havnienses insti- 
tute in Specula Punivenketeies per T aestsca besiapate m Mer- 
zianum ab Anno 1861 ad Annum 1867,” and his other ae 
works. The President will explain to the meeting the grounds of 
ei award after the Annual Report.— Monthly Notices, February, 
4. Fall of a meteor in Iowa.—A meteor fell in Iowa on the 
night of Feb. 12th with loud detonations. The principal portion 
of the fragments from the stone have been secured for the lowa 
State University by Prof. Leonard. 
