PROGRESS OF METEORIC ASTRONOMY 4 49 



of which our nocturnal skies gave clear evidence, were but the 

 debris of ancient disintegrated comets distributed into streams 

 of particles still owning allegiance to the sun. As the earth 

 in her annual round became immersed in these streams, num- 

 bers of them encountered our atmosphere and were consumed. 

 Their average heights while undergoing combustion were 

 about 70 to 50 miles, and their velocities 34 miles per second. 



There were four apparently very certain agreements 

 between comets and periodical meteor showers found by 

 Schiaparelli and his contemporaries, and further coincidences 

 of a similar kind were expected to present themselves. The 

 radiant points of comets and dates of rencontre or nearest 

 approach of the cometary and terrestrial orbits were computed 

 by Weiss and A. S. Herschel, but no further instances of 

 a definite nature were observed. The January, October, and 

 December meteors apparently had no parent comet which 

 could be discovered. And though there were some fairly 

 good cases of near resemblance between the orbits of certain 

 comets and minor meteoric displays, yet there was no absolute 

 proof of connection. Even to this day the list of such 

 associated meteor showers and comets has not been extended 

 if we except the doubtful case of the May Aquarids and Halley's 

 comet. This year ought to provide us with new evidence on 

 the latter, for there should occur a brilliant shower in May 

 if the meteors are dependent on Halley's comet for their 

 supplies. The shower was discovered by Tupman in 1869-70, 

 and it certainly forms a complete ellipse, some of the meteors 

 being visible every year. At the period Tupman recognised 

 it as a specially brilliant shower of meteors the comet was 

 near aphelion. 



It is often the experience that after a branch of science has 

 received a great impetus from several noteworthy discoveries, 

 there results a period of quiescence — for some years, perhaps 

 for a generation, no further striking advances are effected. 

 This has been exemplified in meteoric astronomy. During 

 the last forty years we have no brilliant successes to chronicle. 

 Much has been done, it is true; many thousands of observations 

 — more accurate and reliable than those of the older school — 

 have been accumulated. Our knowledge of the radiant points 

 both of the major and minor systems is now more complete 

 and exact than before, and many hundreds of the real paths 



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