16 



REPORT — 186], 



large iron masses brought to light near Melbomiie in Australia, and other facts 

 full of interest, are keeping alive the attention of philosophers. 



Having joined my excellent fiiend Dr. Homes in the wish to enlarge our Impe- 

 rial Collection of aerolites, I have from time to time had to give notice of several 

 newly observed facts, and at each step to endeavom- to accoimt for some one or 

 other peculiarity. As a result, it seemed to me that I had arrived at a pretty com- 

 plete theory both of the circumstances attending the fall of meteorites, and the 

 conditions of theu- consolidation before they entered our atmosphere. 



Explanations relative to the tellimc fall of aerolites, though more known than 

 formerly, are still not devoid of many difficidties ; but these are far surpassed by 

 the difficidties attending the cosmic question, which in fact amoimt to nothing less 

 than a complete theoiy of the original fonnation of celestial bodies generally, at 

 least of the two which come into contact with each other, the aerolite and our own 

 planet. I beg leave to begin with some considerations on the first of these ques- 

 tions. 



1. The Phenomena of the Fall of Aerolites. — ^There can be no doubt relative to the 

 fact that the crust of aerolites, and their body or mass, are foimed in two difierent 

 ways, the one by superficial melting, the other by long-continued consolidation. 

 The fomi of aerolites beti-ays them" originally to have been frapnents. This is 

 most universally gi-anted. In this direction Sir David Brewster and Humboldt 

 gave their verdicts ; this also has been placed forward by Lam-ence Smith and Mr. 

 Greg. " Viewed from most positions, the largest meteoric stone (that of 103 lbs. 

 weight, in Marietta College, Ohio, fi-om the faU of May 1st, 1860) is angidar, and 

 appears to have been recently broken from a larger body." Many other examples 

 might be adduced. 



It is well known that in some cases, as at Sti-akowitz, on November 28th, 1859, 



and Pegu, December 27th, 1827, the semblance of enlarging and approaching aero- 



litic fireballs has been observed and _. 



described. In these cases the altitude ^^' 



and geogivaphic orientation should be 



carefidly inscribed in a diagram like 



fig. 1, in order to be able, by comparison 



with the exact time of hour, day, and 



year, to find the region fi'om whence 



they travelled to meet om- earth. A B 



(fig. 1) would be the track of a meteor 



an-iving from an altitude of 75° in the 



N.N.E., and exploding or extinguished 



at an altitude of about 40°, while C D 



might denote a meteor that seemed to 

 ... ... 



N. 



N.E. 



E. 



S.E. 



60= 



H. 



60° 



30° 



N.E. 



S.E. 



travel horizontally from 45° N.E. to 4.5° 

 S.E., its true com-se being fi-om N. to S., 

 but visible fi-om the side. Observations fi-om several distinct places, when combined 

 together, will allow the real ti-ack to be ascertained with considerable accm■ac3^ 

 This was finely exemplified in the Ohio fall of May 1, and in the gi-and meteor of 

 Jidy 20th, 1860, of Elmii-a, Long Island, and other places in the United States. 

 _ Viewed fi-om a distance, there is an impression on the eye of a fireball, some- 

 times more or less lengthened, or ending in a sharp pointed tail, and movino- with 

 amazing velocity. When viewed very near, aerolites have been seen to fall down 

 like any other stone, and -with no greater velocity. 



The velocity of meteors varies fi-om 20 to upwards of 140 miles (4 to 23| Ger- 

 man miles), according to joint observations of Julius Schmidt at Bonn (now at 

 Athens), Heis at Aix la Chapelle, and Houzeau at Mons, as recorded in Humboldt's 

 ' Cosmos.' This wonderfid velocity may be compared -wdtli that of phenomena 

 familiar to us upon ovu- own planet. Commander JM. F. Maiu-y, U.S., quotes fi-om 

 Sir John Herschel's ai-ticle " Meteorologj'" in the 'EncyclopiediaBritannica,' 1857, 

 the velocity of 92 English miles in an hour for a " Devastatino- Hmi-icane," or only 

 1-34-9 feet in one second of time, with a horizontal pressure of 37-9 lbs. to a squai-'e 

 foot. The following data are given in Rouse's Anemometric Tables in the Report 

 of the Tenth Meeting of the British Association, &c., at Southampton, in Septem- 

 ber 1846. (London, 1847, p. 344) :— 



