40 The Coming Meteor Shower. — The Spectra of Meteors. 



earth's surface, will make its appearance — periiaps for the last 

 time in the present century — either on the morning of the 

 18th, or on the 14th November." 



The meteors should be especially looked for between mid- 

 night and sunrise, and may be expected in greatest abundance 

 between three and four a.m. " They proceed, with few excep- 

 tions, from a common centre in some part of the Constellation 

 Leo.'" Mr. Herschel observes that "between the 13th of 

 October and the 12th of November, during the years from 

 A.d. 903 to 1833, not less than thirteen great star showers 

 have been recorded. They are separated from each other by 

 the third part of a century, or by some multiple of this period, 

 and are periodical reappearances of one grand meteoric shower, 

 viz., that seen by Humboldt in 1799, and by Olmsted in 1833, 

 the star shower expected to return in the present year, aud 

 known by the name of the ' c great November shower." Its 

 contact with the earth takes place one day in the year at each 

 of its principal returns. According to the exact calculations 

 of Professor Newton, "the next passage of the earth through 

 the centre of the meteoric group will take place two hours 

 after sunrise at Greenwich on the morning of the 14th of No- 

 vember, 1866." A watch on the morning of the 13th is re- 

 commended, "as the moment of greatest brightness may fall 

 one day before the predicted time." On the 13th of Novem- 

 ber, 1 865, first-class meteors were seen at Greenwich at the 

 rate of 250 per hour, and the " maximum display of the No- 

 vember meteors expected in 1866 is several hundred times 

 greater than that observed at Greenwich on the 13th of No- 

 vember, 1865. Two hundred and forty thousand meteors are 

 computed by Arago to have been visible above the horizon of 

 Boston on the morning of the 13th of November, 1833." 



The average height of shooting stars at the middle of 

 their apparent paths is not quite sixty miles above the earth. 



Mr. Herschel points out a singular difference in the be- 

 haviour of shooting stars and aerolites, or meteoric stones. 

 The meteoric stones most frequently fall after mid-day, 

 between noon and nine p.m., while the shooting stars are most 

 abundant after midnight ; and only one stone has been known 

 to fall on the 10th of August or the 13th of November, when 

 shooting stars are most numerous. 



A point of importance to be ascertained by means of the 

 "Meteor Spectroscope" is, whether shooting stars and their 

 luminous trains are composed of porous matter, or of solid 

 matter, perhaps in a finely divided state, as is presumed. 



The anticipated splendour of the November shower should 

 not be permitted to divert attention from the smaller shower 

 expected on the night of August 10. 



