204 CARNEGIE INSTITUTION OF WASHINGTON. 



the)^ may have had it. In their different parts they may present 

 the required structural characteristics. I see no reason to doubt 

 that the asteroids and sateUites have been subjected to deformations 

 attended by fractures, brecciation, veins, sHckensides, and similar 

 dynamic phenomena. Eruptive and explosive action as well as the 

 impact of falling bodies from the exterior may have contributed 

 various forms of fragmental and amorphous material. The absence 

 of a protecting atmosphere subjects their surfaces to the full striking 

 force of falling bodies, and also the disrupting effects of extreme 

 changes^ of temperature. On the exterior, amorphous masses, as 

 well as glassy and cryptocrystalline rock, may not improbably be 

 formed, while at greater depths the varying conditions of pressure 

 and temperature requisite for the more complete and coarser crys- 

 tallizations may probably be present. The hydrocarbons may be 

 assigned to inorganic action within the asteroidal body, the material 

 being derived from the hydrogen and carbon gases so abundantly 

 occluded in meteorites and crystalline rocks, the requisite tempera- 

 tures and pressures being supplied by the internal compression of 

 the body. 



In these small bodies, then, it is perhaps possible to find that 

 extraordinary combination of conditions which the nature of the 

 meteorites implies. 



It remains to postulate a means of disruption and dispersion by 

 which the disrupted fragments shall be given the erratic courses and 

 the high velocities which meteorites possess, while at the same time 

 the structural features, sometimes rather perishable, shall escape 

 destruction by liquefaction or extreme pulverization. 



Any supposed explosion from an internal .source is unsatisfactory, 

 because it is difficult to assign a probable and sufficient cause for an 

 explosion capable of imparting a velocity of several miles per second, 

 which would probably be required to disperse the fragments beyond 

 the control of the system to which the bod}' belonged, and because 

 if such sufl&cient explosion were realized, it must apparently wreck 

 many of the peculiar meteoritic structures. 



Collision with some other body at a high velocity would be suflS- 

 cient to disrupt the body and drive its fragments away with the 

 requisite velocity, but the imminent danger of liquefaction by the 

 inevitable heat of the impact or of extreme pulverization of the 

 fragile material rai-ses doubt as to the adaptability of collision to 

 give origin to the hydrocarbon and some of the stony meteorites of 

 large .size, while it might well give rise to minute meteorites. The 



