Proceedings. Xxxi 
materially change the comet’s course, but with our four big 
brothers—Jupiter, Saturn, Neptune, and Uranus—the case is 
different. Their distance from the sun adds to the effect of their 
enormous mass in two ways. It increases their power relative 
to the sun, and the comets pass them at speeds only fractions of 
their twenty-six miles per second past us. The consequence is 
that they each have their special band of captives. These are 
easily recognised by their orbits having been shortened down in 
space and time. Jupiter’s captives go at most a little further 
from the sun than himself, and take only eight years or less to 
revolve. Among them is Biela’s comet, which gives us the 
Andromedes, cutting our orbit every 63 years. The Perseids 
belong to Tuttle's comet, a captive of Neptune; while the 
Leonids follow Temple’s comet, slave to Uranus, due next year 
and every 334 years following. This comet is believed, as stated, 
to have been captured in 126a.p. By 902 its orbit was so / 
shifted as to cut ours. The main body of the comet’s trail 
collided with us on October 19th (n.s.), and has continued to do 
so ever since.. The day may come when another encounter with 
Uranus will switch it off again to the depths of space. But the 
main body of meteors would remain. Planetary action induces 
an advancing date in the Leonid shower, as shown by the sub- 
joined table of records :— 
A.D. 
902,10 mo.19th ...... The Arabic ‘ Year of Stars.’ 
954e ee eOOGb Jee. .< ‘Signs in the heavens as stars falling.’ 
TOODES ho. eV ep Sse. ‘Thousands of small stars.’ 
AOD ie io MOSS. was ‘Stars were seen to fall from heaven.’ 
1202) 15,0 26th fe: ‘Towards daybreak thousands of 
shooting stars . . . flew about 
like grasshoppers.’ 
T3665... 55. Oui. ceo ‘Such numbers that the sky and air 
seemed to be in flames.’ 
1533, 1lmo. 38rd ...... ‘Many thousand stars .. .fall and 
: : dash together.’ 
1602, ,, Gilt. snes ‘Many hundred . . . in the same 
direction.’ 
98... 35 Oth? wkests Seen at Geneva. 
1766, _ ,, Othy cze.05 In South America. 
ally 08 ee gt) a Gags Bo Greenland to South America. 
1885. °=455, slot ees North America. 
S66; . 2, » Lothar Europe (morning of 14th). 
This table tells us plainly that the shower may be expected 
about the years ’33, 66, and ’99 of each century, and has now 
been so recorded without any break for four times in succession. 
At its last appearance it was foretold as probable. Certainty of 
observation cannot be assured for two reasons. The stream, 
though so compact as to give only one chief display per revolu- 
