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Recent contributions to Astro-Mete orology. 203 
tance from the earth to the sun being unity). The rarity of the 
matter in this cloud is regarded such that the mutual attraction 
of the particles may be disregarded. This cloud of particles is 
then supposed to have a velocity (relative to the sun) perpen- 
dicular to a line drawn to the sun, one twenty-thousandth of the 
mean velocity of the earth, or about one hundred yards a minute. 
€ several particles will move in elliptic orbits about the 
sun, but these ellipses will not be exactly equal. Mr. Schiapa- 
relli shows that a cloud, of spherical form at first, would be de- 
formed, little by little, and ultimately drawn out so as to have a. 
very small transverse section. It will now lie along a parabolic 
observed for hundreds or thousands of years, like that of August, 
Aw. Jour. 8c1—Sxconp Sznizs, Vou. XLIII, No. 120.—Mar, 1867. _ 
: “ 4, 38 
