SCIENCE. 



[N. S. Vol. hi. No. 53- 



he located a mining claim ; and going to 

 the city of Albuquerque, he announced that 

 he had a vein of pure iron 40 yards wide 

 and two miles long, and offered to sell his 

 property to a railway company. The 

 samples he submitted were examined by an 

 assayer, and the officers of the company 

 gave consideration to his proposal, agreeing 

 to send a representative to examine the 

 property. The negotiation was not con- 

 cluded, because Mr. Craft, having bor- 

 rowed money on the strength of his great 

 expectations, mysteriously disappeared, but 

 the incident served to give information 

 of the locality to a scientific observer. 

 The assayer forwarded a piece of the iron 

 to the late Dr. A. E. Foote, the mineral- 

 ogist, who visited the place, collected a 

 quantity of the iron and examined the 

 crater. In the summer of 1891 he com- 

 municated his observations to the American 

 Association for the Advancement of Sci- 

 ence, * which that year was the guest of 

 the scientific societies of Washington, and 

 his paper aroused much interest. For the 

 crater of non-volcanic rock he offered no 

 explanation, but the ii'on he pronounced of 

 celestial origin — a shower of fallen meteors. 

 It has long been known that many of the 

 bodies which reach the earth from outer 

 sj)ace are composed of iron, and that such 

 iron is of peculiar character, having a cer- 

 tain crystalline structure, being alloyed 

 with nickel, and including nodules of 

 certain substances which are not found in 

 any other association. So Doctor Foote, in 

 characterizing the iron as meteoric, merely 

 referred it to a well-established class. His 

 explanation was not tentative, but final, 

 and has not been called in question by any 

 subsequent investigator. 



In the discussion following the reading of 

 his paper a new hypothesis was proposed, 



* A new locality for meteoric iron with a prelimi- 

 nary notice of the discovery of diamonds in the iron. 

 Proe. Am. Ass. Adv. Science, Vol. 40, pp. 279-283. 



and as this was offered by myself I can 

 trace its origin with comparative confi- 

 dence. The crust of the earth is not 

 equally dense at all points, but some parts 

 are heavier than others. Not only are 

 there variations from hill to hill and from 

 formation to formation, but the continents 

 are in general composed of lighter mate- 

 rials than the ocean beds, and one side of 

 the sphere is so much heavier than the 

 other that its attraction pulls most of the 

 water away from the other side. Among 

 the various theories that have been pro- 

 posed for the origin of the planet there is 

 one which ascribes it to the falling together 

 under mutual attraction of many smaller 

 celestial bodies, and it has been suggested 

 that the variations in the crust may repre- 

 sent original differences of the concurrent 

 masses. Speculating on such lines I had 

 asked myself what would result if another 

 small star should now be added to the 

 earth, and one of the consequences which 

 had occurred to me was the formation of a 

 crater, the suggestion springing from the 

 many familiar instances of craters formed 

 by collision. A raindrop falling on soft 

 ooze produces a miniature crater ; so does 

 a pebble thrown into a pool of pasty mud. 

 A larger crater is made when a steel projec- 

 tile is fired against steel armor plate ; and 

 analogy easily bridged the interval from 

 the cannon ball to the asteroid. So when 

 Dr. Foote described a limestone crater in 

 association with ii-on masses from outer 

 space, it at once occurred to me that the 

 theme of my speculation might here find its 

 realization. The suggested explanation as- 

 sumes that the shower of falling iron masses 

 included one larger than the rest, and that 

 this greater mass, by the violence of its col- 

 lision, produced the crater. Here again you 

 will observe that a single theory explains 

 the crater, the iron and their association. 



The thought of examining the scar pro- 

 duced on the earth by the collision of a star 



