Feb. 13, 1879] 



NATURE 



341 



tion, as descriptions and newspaper notices show in every 

 country in Europe. But no person seems to have con- 

 nected it with any previous shower, nor does it appear 

 that any one gave a hint of the true nature of the 

 phenomenon. 



The next year there appeared in this country, on the 

 morning of November 13, a more brilliant shower, which 

 some present doubtless ^vitnessed. Through the morning 

 hours of that day the stars shot across the sky like the 

 flakes of snow in a snowstorm. Not a little difference 

 was there in the way people looked at it. The negroes at 

 the south thought the day of judgment had come. The 

 owner of a plantation told me that his negroes had 

 gathered in the "praise-house," and that he on being 

 waked went down to quiet their fears. They had con- 

 cluded not to call "Missus," as she would soon hear 

 Gabriel's trumpet, and they well knew that she was 

 ready to go. A student here in College was going to 

 prayers, and saw a ball of light pass across the half 

 lighted moving sky. He rubbed his eyes, thinking that 

 something was the matter with them. A second flight 

 made him sure that his eyes were troubled, and he 

 looked down and hurried on to chapel. A servant girl 

 by chance returning home in the early morning, saw it, 

 but said nothing until it was talked of the next day. 

 *' Oh," said she, "I saw that." "Did you? Why did 

 you not call us ? " "Really, I didn't know but that the 

 stars went out that way every morning." Prof. Twining 

 saw it, and observing that all the flights were away from 

 one point in the heavens, and that that point moved 

 along with the stars as they rose in the morning sky, he 

 said, " These are not, as some say, meteorological pheno- 

 mena ; they are not, as others say, electric ; these are 

 bodies coming to us from beyond the air, and they belong 

 to astronomy." This was the first definite proof of the 

 cosmic origin of meteors. 



Nine hundred and thirty-one years earlier, that is, in 

 the year 902, there was a like brilliant shower of fire. A 

 cruel Aghlabite king then reigned at Tunis . He had driven 

 the Christians out of Sicily, penning up the Bishop of 

 Taormina and the remnant of his people in the church, 

 and burning it and them together. He had crossed to the 

 mainland, and was besieging Cosenza, then an important 

 city of Calabria. He suddenly died, and the flying monks 

 were relieved of their terrors. They connected his death 

 with the star-shower which occurred at or near the same 

 time, and in all the annals it is repeated in varied phrases 

 that on the night when King Ibrahim Bin Ahmad died an 

 infinite number of stars scattered themselves like rain to 

 the right and left. 



Between the years 902 and 1799 the November 

 meteors were seen in unusual numbers in at least nine 

 different years. The showers in the table which I show 

 you are not selected out of an indefinite number in our 

 histories. On the contrary, they are nearly all which we 

 have found in the records as having occurred near that 

 time of year. 



Epochs of Novembir Star-Shozvers 



Year. Day. 



902 October 13 



\ 931 ,, 16 



\ 934 „ 14 



1002 „ IS 



iioi ,, 17 



1202 „ 19 



1366 „ 23 



'533 ,, 25 



1602 „ 28 



1698 November 9 



1799 •• „ 12 



j^^32 13 



I ^^3Z ., 13 



1863-68 „ 14 



Notice now in this table that the showers came either 

 near the beginning or near the end of the first third, or 



else near the end of the second third of the century. In 

 other words, they all come near the end of a cycle whose 

 length was 33J years. Again, notice that the day of the 

 month advanced with slight irregularity about three days 

 in the century. The large advance of twelve days 

 between 1602 and 1698 is due to the change of ten days 

 in the reckoning in passing from old style to new style. 



I have added, as you see, the six years from 1863 to 

 1868, in each of which, but especially in the latter three, 

 these meteors came, as we had expected, on the morning 

 of November 14. They seemed in all these years to 

 pass, as they did in 1833, across the sky, as though going 

 away from the constellation Leo, or rather from the 

 sickle in Leo. This means that the small bodies really 

 came into the air in parallel lines, the apparent radiation 

 being the way in which parallel lines appear to us. There 

 can be no doubt that there was the same parallelism of 

 paths in all the earlier star-showers. 



Here we hare a group of solid bodies coming into the 

 air all moving in one given direction. They come to us 

 only on a particular time in the year, for the slow change 

 from the middle of October to the middle of November 

 can be explained. They come to us only at intervals of 

 about a third of a century. These facts can only be satis- 

 fied by supposing that vast numbers of these small bodies 

 are moving in a long thin stream around the sun, and 

 that the earth, at the proper times, plunges through them 

 taking into the air each time some scores of millions of 

 them. Each of them must be moving in an orbit having 

 the same period as every other, and approximately the 

 same path. 



Now it may be shown that there are but five orbits 

 about the sun that can meet these conditions. Further 

 than that, there is but one of these five that can explain 

 the change of date from the middle of October to the 

 middle of November, and this fifth one does explain the 

 change perfectly. I cannot in the time you kindly grant 

 me give in such detail that you can clearly understand 

 them, the reasons for thus limiting the path of the meteo- 

 roids first to five possible orbits, and then to one of these 

 five. I must ask you to accept the statement in view of 

 the fact that no astronomer has, so far as I know, ever 

 questioned the proofs of it. 



That orbit is one which is described in 33:^ years. The 

 meteoroids go out a little further than the planet Uranus, 

 or about twenty times as far as the earth is from the sitn. 

 While they all describe nearly the same orbit they are not 

 collected in one compact group. On the contrary they 

 take four or five years to pass a given place in the orbit, 

 and are to be thought of as a train several hundred mil- 

 lions of miles long, but only a few thousands of miles in 

 thickness. 



Now right along with this train of meteoroids travels a 

 comet. It passed the place where we meet the meteo- 

 roid stream nearly a year before the great shower of 1866, 

 and two or three years before the quite considerable 

 displays of 1867 and 1868. It was therefore well towards 

 the front in the great procession. 



How came it that this comet and the meteoroids thus 

 travel the same road — the comet with the meteroids and 

 the meteoroids with each other ? The plane of the comet's 

 orbit might have cut the earth's orbit to correspond with 

 any other day of the year than November 15. Or cutting 

 it at this place the comet might have gone nearer to the 

 sun or farther away. Or, satisfying these two conditions, 

 it might have made any angle from zero to 180° instead 

 of 167°. Or, satisfying all these, it might have had any 

 other periodic time than 33 j years ; even then it might 

 have gone off" in any other direction of the plane than that 

 in which the meteoroids were traveling. All these things 

 did not happen by chance ; there is something common. 



The comet which I have named is not the only one 

 that has an orbit common with meteoroids, though it is 

 the only case in which the orbit of the meteoroids is 



