880 PROCEEDINGS OF THE ACADEMY OF [DeC, 



fragments and the silica, which forms part of the rim, or on the sur- 

 rounding limestone plain. 



On April 11, 1904, it was my good fortune to observe, while at 

 Pearce, Arizona, between five and six o'clock in the afternoon, a very 

 brilliant meteor. This same meteor was observed at Tucson, Arizona, 

 by Mr. Holsinger, who had been in charge of our exploratory work for 

 some time previous to this. He was at the time over seventy miles 

 distant from Pearce in an air line. It is a source of much regret that 

 the sun was shining at the time, for otherwise the spectacle would have 

 been a most brilliant and instructive one. As it was, however, the 

 meteor was so large and so brilliant that the following facts could be 

 most clearly determined : The head of the meteor was blue-white in 

 color; from this head there seemed to dart from time to time, and almost 

 from the moment the meteor became visible, many jets of bluish-colored 

 light. Behind the meteor was a glorious comet-like tail, the color of 

 which was generally yellow. From behind the meteor and out of this 

 tail there appeared from time to time, and after the meteor had been 

 visible for an appreciable length of time, great flaming drops, not 

 unlike drops of burning tar. These rapidly fell behind the meteor, 

 being distanced by it. In shape they were, generally speaking, some- 

 what like a gourd, with the small ends, which as I remember seemed to 

 bend slightly downward, pointing toward the rapidly receding meteor. 

 I counted as many as five of these drops. Mr. Holsinger thought he 

 saw more than five. 



Bearing in mind what I have related above, I shall now offer an ex- 

 planation of the difference in distribution of the pieces of metallic 

 meteoric iron and the so-called shale balls, realizing fully, however, that 

 in the first place not enough work has been done to state with positive- 

 ness that no large pieces of iron are to be found in the fragmentary 

 material forming in great part the slopes of the mountain, and in the 

 second place that the explanation which I offer may be proved to be an 

 erroneous one. I am inclined to believe that many of the thousands 

 of pieces of metallic meteoric iron which have been found distributed 

 around Coon Mountain, and which are generally known by the name of 

 the Canon Diablo siderites, were pieces that were torn loose from the 

 surface of the meteor when it entered the earth's atmosphere by the 

 violent expansion strains set up because of the intense coldness of the 

 main body of the meteor, which of course was cooled to the temper- 

 ature of outer space, and the intense heat immediately generated upon 

 the entrace of the meteor into the earth's atmosphere. This would 

 explain the darts of light which Mr. Holsinger and I saw going out of 



