T. C. CHAMBERLIN 



a measure of the melting effects. This would be a tempting line 

 of attack but is quite inadmissible because the mechanical effects 

 alone call for more energy than can be reasonably assigned to the 

 meteoritic material found. The only safe recourse is the direct 

 evidence. The heating effects implied by the direct evidence are 

 singularly small compared with the mechanical effects. To a 

 considerable, but not closely determined, extent, the crushed 

 sandstone shows incipient schistosity with partial metamor- 

 phism, obviously a compressive effect, the heat of which did not 

 rise to the grade of fusion. To a considerably smaller extent, if 

 I interpret the descriptions correctly, the crushed sandstone shows 

 the early stages of fusion, while some of this portion has become 

 inflated and pumaceous, but no appreciable masses were left in 

 the state of glass or other completely fused product. If fully 

 melted matter was formed at all, it was probably dispersed by the 

 explosive reaction. It seems quite clear that the portion which 

 became vesicular did not become fully fused and fluent, for, in 

 part at least, the bedding lines were not wholly obliterated. These 

 portions seem, however, to have been rendered distinctly viscous 

 and susceptible of inflation. This must probably have taken place 

 during the resilience which followed the compression. The internal 

 gases could scarcely have puffed the viscous rock while the intense 

 pressure of the impact was on. If, on the other hand, they had 

 remained viscous until the pressure from the falling back of the 

 exploded debris was brought to bear, they would have collapsed, 

 at least in all deeply buried portions. Apparently they had 

 cooled in their inflated state while the pressure was off. It seems, 

 therefore, that there was practically no liquid rock left when the 

 explosive reaction was over. This is a matter of radical importance 

 in its bearings on the question of producing a holo-liquid earth by 

 such impacts. It shows that a very high proportion of the energy 

 of impact was converted into another mechanical form, not into heat. 

 There is no question about the greatness of the energy of impact; 

 the mechanical work involved in the formation of the crater and 

 of its rim, as also in the crushing and scattering of the debris, demon- 

 strate that. And yet there is no evidence that this violent impact 

 left even the smallest pool of lava. The significant feature of the 



