Jant>ary 3, 1896.] 



SCIENCE. 



the rim was bulkier on tlie east side than 

 on the west, and that nearly all the iron 

 had been found east of the crater. The 

 new explanation was that a star, falling ob- 

 liquely from the western sky, struck the 

 earth and bounded off, finally coming to 

 rest at some point farther east. The idea 

 was of course derived from the ricochet of 

 projectiles; I had seen the mark left by a 

 rifle ball where it rebounded from a plowed 

 field.- This explanation could be tested by 

 a simple examination of the topographic 

 form ; and it may be as well to anticipate 

 here the order of the narrative, and say 

 that the form of the crater was found to be 

 quite inconsistent with the ricochet hypoth- 

 esis. The difference of the two diameters 

 is quite small ; the eastern rim is but little 

 more massive than the western; and the 

 dislocation of the rocks in the western rim 

 is of such character that it could not have 

 been produced by a body descending ob- 

 liquely toward the east. 



Arriving at the crater we spent two 



Fig. 2. — The upper diagram is profile across the 

 crater ; the lower, a cross-section of the rim. 1, 

 limestone. 2, sandstone. 3, red shale. 4, crushed 

 rock. 5, loose blocks of limestone and sandstone. 

 6, talus pf debris fallen from 1 and 2 above. 



weeks in topographic and magnetic surveys 

 and the study of local details. The di- 

 ameter of the bowl, measured from rim to 

 rim, is about three- fourths of a mile. Its 

 depth below the rim is from 550 to 600 

 feet ; below the plain, 400 feet, the rim be- 

 ing 150 to 200 feet high. The rim is in 

 part composed of limestone strata like 

 those which underlie the plain, but turned 

 up, so as to incline steeply away from the 

 hollow ou all sides. On the inclined strata 

 rests a mantle of loose fragments which are 

 in part of limestone and in part of sand- 

 stone. The limestone masses are fragments 

 of the formation occurring just beneath, 

 and the sandstone masses are fragments of 

 a formation which underlies the limestone 

 formation. Most of the masses are of mod- 

 erate size, but others are large, the lime- 

 stone reaching a diameter of 60 feet, and 

 the sandstone about 100 feet. (Plate 2. 

 Figs. 1-4.). They are irregularly mingled, 

 one material predominating in one tract 

 and the other in another. The limestone 

 is the more conspicious because withstand- 

 ing better the attacks of the weather. In 

 fact the larger blocks of sandstone have 

 been so far washed away that they do not 

 project above the surface. From the crest 

 of the rim outward this loose material oc- 

 cupies the surface for an average distance 

 of half a mile, being characterized by roll- 

 ing or hummocky topography. At greater 

 distances it is thinly spread and the con- 

 stituent blocks are small. At one mile it is 

 represented only by scattered fragments, but 

 these continue with diminishing frequency 

 to a distance of three and a half miles. 



Inside the rim the edges of limestone 

 strata occupy the slope for a space of 150 

 to 250 feet. They are succeeded in several 

 places by sandstone strata, but the sand- 

 stone does not hold its original relation to 

 the limestone; it is separated by a vertical 

 zone of crushed rock, and there is other 

 evidence that it has been faulted upward. 



