METEORS AND METEORITES. 



547 



ment he followed for more than a second. The 

 spectrum was as continuous as that of Capella, 

 and a little more extended ; so that the mass 

 must have heen a solid or liquid substance, and 

 not a gas or incandescent vapor. (See Nebulae, 

 ASTRONOMICAL PHENOMENA, etc.) 



Including, then, the known chemical compo- 

 sition of aerolites, all the lines of evidence go 

 to show that all so-called shooting stars and 

 other meteors are in reality originally so many 

 minute planet-like masses, asteroidal bodies of 

 the least possible magnitudes, just as the aste- 

 roids properly so called are the (as yet) least pos- 

 sible of visible planets. As Faye intimates, there 

 may be a gradation in magnitude of such bodies, 

 from the smallest known asteroids down to 

 masses which- become visible as shooting 

 stars. 



Of the distribution of these bodies, more 

 presently: at least, none of them of a magni- 

 tude approaching that of the asteroids appear 

 to circulate through the spaces traversed by 

 the earth. Some singular confirmations of the 

 views just stated have been obtained. Dr. 

 Schmidt observed some time since, with one 

 of the powerful telescopes of the Observatory 

 at Athens, the explosion of a meteor, the re- 

 sult being a shower of incandescent fragments ; 

 and M. Heis declares that, at 8 h '31 m P.M., 

 October 4, 1864, as he was observing with a 

 telescope the Milky "Way, he distinctly saw 

 where a dark mass slowly moved along the 

 half-illumined sky, eclipsing the stars in its 

 path. Reader, January 21, 1865.) 



Our knowledge of luminous meteors is no 

 longer confined to the rarely occurring and 

 wonderful November star-showers, nor even to 

 such phenomena as the ordinary frequency of 

 meteors at periods like those of November and 

 August. Through the recent labors especially 

 of Prof. Newton in this country, of A. S. Her- 

 schel, Greg, and Sorby, in England, and of 

 Quetelet, Heis, Secchi, Schmidt, and others on 

 the Continent, very much relating to the phe- 

 nomena of meteors in general has already been 

 brought as distinctly within the domain of as- 

 tronomical science as are the orbits and period- 

 ical return of comets. 



The November Period due to a Heliocentric 

 Heteoroidal Ring. Prof. Newton has in the 

 Amer. Jour, of Science, vol. xxxvii., p. 377 

 (May, 1864), a highly interesting and complete 

 discussion of this subject, under the title of 

 " The original accounts of the displays in former 

 times of the November Star-Shower," etc., its 

 conclusion appearing in vol. xxxviii., p. 53 

 a paper in regard to which Mr. Glaisher re- 

 marks, that "it constructs the elements of the 

 November meteoric ring solely from historical 

 data, and in such a manner as to leave very 

 little for further observations to supply." From 

 various works and records are gleaned the dates 

 and descriptions of the great 33-yearly Novem- 

 ber star-showers, beginning with A. D. 902, and 

 ending with the still remembered and very 

 remarkable display of the year 1833. From 



the data thus obtained, the author deduces 

 among others the following conclusions : 



From the middle of the first of the given dis- 

 plays, say October 13th, A. D. 902, at 5 h - A. M., 

 Italian time, to the middle of the last shower, 

 November 13th, 1833, there were 931 (terres- 

 trial) periods, of 365.271 days each. This time 

 comprises 28 cycles, of 33.25 years each, 

 the years 902 and 1833 happening, it would 

 appear, to occupy approximately corresponding 

 places in their cycles. The length of that part 

 of a cycle during which extraordinary displays 

 may occur, is at least 2 years 3 months, while 

 the numbers of shooting stars may be greater 

 than usual for at least 5 or 6 years. The me- 

 teoroidal bodies which afford the November 

 showers, move in a nearly circular orbit about 

 the sun, its inclination to the ecliptic being 17, 

 and their motion in their orbit being retrograde. 

 The revolutions appear to be l + ^sV? m a ter- 

 restrial year ; so that the annual revolution of 

 the ring supposing the showers of A. D. 902 

 and 1833 to have the same places in their 

 cycles occupies 354.621 days; and within the 

 whole time given 959 revolutions, nearly, have 

 occurred. The meteoroidal bodies, however, 

 would appear not to form a ring of uniform 

 density, but a compact elongated group or cloud, 

 its length -^th to T Vth the periphery of the 

 ring actual length more than 40,000,000 miles ; 

 while, if a shower lasts 5 hours, the thickness 

 of the ring would be the distance passed over 

 by the earth in that time x the sine of the 

 inclination of the orbit = more than 100,000 

 miles. Allowing for the earth's attraction, the 

 velocity with which the bodies enter our at- 

 mosphere is about 20.17 English miles per sec- 

 ond. We have most reason to expect the next 

 star-shower on the usual days (November 13th, 

 14th), of the year 1866, and that it will be cen- 

 tral over the western Atlantic. The author 

 does not, however, state this as a prediction. 

 The anticipation implied in the paper, of star- 

 showers in the years 1864-'65, appears scarcely 

 to have been realized. 



Shooting Stars from other Radiants, and 

 Sporadic: Question of Other Rings. In the 

 Amer. Jour, of Science, March, 1865, appears 

 an abstract of another elaborate and highly 

 original memoir by Prof. Newton, which was 

 read before the National Academy of Sciences, 

 August 6, 1864, but of which a bare outline 

 only can here be given. 



The author undertakes to investigate the 

 phenomena of shooting stars generally, as seen 

 on all clear nights; and he makes his table 

 (1798 to 1863), already referred to, the basis 

 of the computations, combining with its data 

 observations from a variety of other sources. 

 Disregarding the instances of which the middle 

 point of path is at altitudes less than 30, or 

 greater than 180 kilometres, he finds for these 

 successive intervals of elevation, 30 60 90 

 120 150 ISOkilom., the numbers of meteors, 

 114, 243, 277, 106, and 57, respectively; the 

 mean altitude of middle point of path being 



