PROGRESS OF METEORIC ASTRONOMY IN AMERICA. 295 
traveling. All these things did not happen by chance; 
there is something common. 
The comet alluded to is not the only one that has an orbit 
common with meteors, though it is the only case in which 
the orbit of the meteors is completely known, aside from our 
knowledge of that of the comet. Every August, about the 
tenth day, we have an unusual number of meteors—a star- 
sprinkle as it has been called. A comet whose period is 
about 125 years moves in the plane and probably in a like 
orbit with these meteors. Near the first of December there 
have been several star-showers, notably one in 1872, and 
these meteors are traveling nearly in the orbit of Biela’s 
comet. In April, too, some showers have occurred which 
are thought to have had something to do with a known 
comet. Thus much as to the meteors of the star-showers. 
The sporadic meteors are with good reason presumed to be 
(and observed facts prove some of them to be) the outliers of 
a large number of meteor streams. 
Considering again the November meteor stream and its 
comet w^e find that the several bodies move along a dbmmon 
path not at all by reason of a present physical connection. 
They are too far apart—in general, a thousand times too far 
apart—to act on each other so much that we may measure 
the effect. Their connection has been in the past. They® 
must have had some common history. Looking now at 
the comets, we see that they have been apparently growing 
smaller at successive returns. Halley’s comet was much 
brighter in its earlier than in its later aj)proaches to the sun. 
Biela’s comet has divided into two or more principal parts, 
and seems to have entirely gone to pieces. Several comets 
have had double or multiple nuclei. In the year 1366, in 
the week after the star-shower, a comet crossed the sky ex¬ 
actly in the track of the meteors. A second comet followed 
in the same path a week after. Both belonged, no doubt, 
to the November stream, and one of them may perhaps have 
been the comet of 1866. 
The November meteor stream is a long, thin one. We 
