16 Field Columbian Museum — Geology, Vol. i. 



fall. At the time of fall of this meteorite three distinct reports 

 were heard and five different fragments were picked up at four places 

 several miles apart. Three of these fragments were found to fit 

 together perfectly and at the points of contact to exhibit no crust, 

 though their other surfaces were coated with it. The point of junc- 

 tion of the other two fragments could also be made out, though this 

 surface possessed a crust hardly distinguishable from that of the rest 

 of the mass. It was also found possible to unite all the fragments 

 into one shell-like mass, showing that this was probably a unit as it 

 entered the atmosphere and that the successive disruptions took place 

 during its passage to the earth. 



Similar variations in crust are observable among the individuals 

 of nearly every meteoric shower, making it seem probable that they 

 are produced by the breaking up of a single individual. 



It should be noted, however, that some authorities prefer to regard 

 the stones of a meteoric shower as members of a swarm of larger or 

 smaller planetary individuals which had a previous independent ex- 

 istence. 



In size, meteorites vary from complete individuals no larger 

 than a pea (Winnebago Co., 340) to the enormous mass of Chupaderos, 

 Chihuahua, Mexico (Model 422) whose weight has been variously esti- 

 mated at from fifteen to twenty- five tons. The Phillips Co., Kansas, 

 meteorite (350) if it reached the earth, as is highly probable, in a 

 single mass, is the largest single aerolite in existence, the aggregate 

 weight of the fragments so far found being 1300 pounds. The next 

 largest is an individual of the Knyahinya, Hungary, fall, preserved in 

 the Vienna Museum, having a weight of 647 pounds. Among the 

 aerosiderites or iron meteorites, however, there are many of greater 

 size and weight, as for example the Cranbourne (68) mass now pre- 

 served in the British Museum, which weighs about four tons, the Red 

 River or Gibbs meteorite (34) in the Yale College Museum, weight 

 1630 pounds, and several Mexican meteorites. 



The chemical study of meteorites has shown them to be made up 

 of elements such as are common upon the earth and has as yet 

 revealed none new to its constitution. About twenty-five have thus 

 far been recognized, of which iron, silicon, magnesium, nickel, sulphur, 

 phosphorus and carbon are the most important. The following list 

 represents all that are known to occur : 



Aluminium Chlorine Iron *Nitrogen Sodium 



Antimony Chromium Lithium Oxygen Sulphur 



Arsenic Cobalt Magnesium Phosphorus Tin 



Calcium Copper Manganese Potassium Titanium 



Carbon Hydrogen Nickel Silicon 



♦Recent investigations by Prof. Ramsay have shown that what has been regarded as nitrogen, 

 is largely made up of argon and helium. See Nature Vol. 5?, p. 2Z\. 



