68 Dr. Walter Flight— On Meteorites. 



and Weston, and finds that not only do the stony meteorites give off 

 a much larger volume of gas at low temperatures, but the composi- 

 tion of the gas in all the cases studied is quite different from that 

 evolved from meteoric iron. In no case among the results obtained 

 with the alloy is the amount of carbonic acid greater than 20 per 

 cent, at 500^, nor than 15 per cent, of the whole quantity evolved, 

 while in every case but one the volume of carbonic oxide is con- 

 siderably larger. In the chondritic meteorites, on the other hand, 

 the per-centage of the latter gas is conspicuously small, while the 

 carbonic acid constitutes more than half the total gas evolved below 

 a red heat, except in the case of the meteorite under consideration 

 which fell at Iowa, and here the per-centage is not much less, espe- 

 cially if we reject the numbers representing the amount obtained by 

 a second and long- continued application of a red heat. At a tem- 

 perature of about 2>5(f it constitutes from 80 to 90 per cent, of the 

 gaseous products, and at 90° it forms more than 90 per cent, of 

 the gas evolved. The hydrogen, on the other hand, progressively 

 increases in quantity with the rise of temperature, and is the most 

 important constituent of the first portions removed at a red heat. 

 The form in which the carbonic acid is occluded is a problem which 

 he cannot at present solve. That it is actually absorbed appears to 

 be certain. That it has been taken up from the atmosphere has 

 been proposed. He finds, however, that the iron of the Iowa 

 meteorite contains no more carbonic acid now than it did at the time 

 of its fall. 



Leonard gives a detailed account of the appearance presented by 

 the meteor, which is stated to have been seen throughout a region 

 400 miles from S.W. to N.E., and 250 miles in breadth. The stones 

 vary in weight from a few ounces to 74 lbs., and the aggregate 

 weight is 500 lbs. ; the area over which they were scattered appears 

 to be seven miles in length, and four miles at its greatest breadth. 

 A plan of the townships included in this area is given in Leonard's 

 paper, and it shows where the chief stones fell. By reason of the 

 frozen condition of the ground at the time of the fall, and the low 

 angle of descent, it appears probable that almost all the fragments 

 which fell have been secured. The velocity of the meteor has not 

 been satisfactorily determined ; it ajjpears probable that during the 

 last 60 or 70 miles of its course it travelled at the rate of from six to 

 seven miles per second. 



An interesting pamphlet by Mr. Irish, C.E., deals with the appear- 

 ance presented by the meteor. He has incorporated in his paper a 

 number of letters received from observers stationed over a wide area, 

 describing their impressions as to its altitude, velocity and appear- 

 ance ; and he has given a drawing of the meteor, and prepai'ed a 

 map of the district, showing the projection of its path through the 

 air. I learn by a recent letter from Mr. Irish that two blocks, one 

 weighing 72 lbs., the other 48 lbs., which evidently formed one and 

 the same mass which was disrupted during the descent, have since 

 been found : and the aggregate weight of the stones now collected 

 cannot be less than 700 lbs. I am also indebted to Mr. Irish for six 



