116 Progress oj Science respecting Igneous Meteors. 



Upon this Professor Silliman remarks, " its size, as conjec- 

 tured by Mr. Turney, is much less than the estimated size of 

 that meteor*." As the examination of the conjecture would 

 lead me into a question which I am not yet prepared to dis- 

 cuss, viz. whether, when a meteor of this description explodes, 

 its entire nucleus falls to the earth in the form of meteorites, 

 as commonly believed ; or whether a portion only of its sub- 

 stance is separated and cast down, so that the main body of 

 the meteor still proceeds on its course, as some writers have 

 contended, and in which latter case the same meteor may be 

 seen repeatedly ; I must omit it for the present : some re- 

 marks however upon a subject which is involved in Professor 

 Silliman' s objection, will be found in a subsequent page of 

 this section, where Professor Dean's estimate of the magni- 

 tude of the great fire-ball of 1822 is stated. 



The collection of observations on the great meteor that 

 passed over several of the northern Anglo-American States, 

 on the 9th of March 1822, together with the calculations 

 founded on some of them by Professor Dean, are among the 

 most interesting of the kind ; and may rank with the obser- 

 vations and deductions respecting the Fire-balls of 1719, 1758, 

 1771, and 1783, given, respectively, by Dr. Halley, Sir John 

 Pringle, M. Le Roy, and Mr. Cavallo and others. In some 

 respects, indeed, they are peculiarly instructive. 



From a comparison of these observations, it appears that 

 this meteor was seen over a tract of country including the 

 space from Portland in the state of Maine, in long. 70° 20' 

 W. to Oxford, in Chenango county, New York, in about long. 

 75° 45'; and from some part of Rhode Island, lat. at most 

 42° N., to Quebec, lat. 46° 50'. The tract was no doubt con- 

 siderably greater in extent, but the foregoing are the only de- 

 finite limits for which data are afforded. The path of the me- 

 teor was from north-east to south-west; or more accurately, 

 according to Prof. Dean, the direction of its motion was south 

 34° west: and according likewise to his computations, it must 

 have traversed a space of about two hundred and fifty miles, 

 between the zenith of Wilkesbarre in Pennsylvania, and that of 

 Essex, a village on the western shore of Lake Champlain. 



Mr. Doty, who observed this meteor from a point of the 

 Mohawk turnpike road, near Canajoharie, in the state of 

 New York, and who appears to have had it nearly in his 

 zenith, estimated its diameter at from twenty to thirty feet. 

 To other observers, according to their situation, and accord- 

 ing, likewise, as I shall endeavour to show in the sequel, to 

 the actual change of bulk and of figure in the meteor, it ap- 



* American Journal, vi. p. 3)!). 



pea red 



