DIASTROPHISM AND THE FORMATIVE PROCESSES 151 



heavy from light material, but it will be helpful to keep in mind 

 bodies of both the larger and the smaller orders. So far as the 

 selection and the segregation of matter is concerned, there was no 

 essential difference between the planets and the satellites as 

 such, for each arose from independent portions of the erupted 

 sun substance. The critical elements were the spheres of control 

 dependent on mass and dynamic environment. 



While we must await further light on the precise modes in 

 which solar gas-masses are shot forth and the circumstances that 

 induce them, we may be quite sure that, as they passed away from 

 the sun into the outer field of its control, certain influences inevi- 

 tably affected them. They must have been under the control of a 

 projectile force sufficient to overcome the larger portion of the sun's 

 total attraction. In this controlling force we may safely assume 

 that there were conjoined (i) an original projectile force having 

 its origin in the interior of the sun, (2) radiation pressure from 

 the sun after the mass had left its surface, and (3) electrical effects, 

 attractive and repellent, as also ballistic, that is, due to the mo- 

 mentum of electrons and alpha particles shot forth from the 

 sun and caught by the escaping mass. Just what proportionate 

 parts these co-operating agencies played in the total work of 

 projection, we need not now inquire. It is taken for granted, 

 since it is almost inevitable, that in escaping from the sun the gas- 

 masses acquired some measure of rotatory motion, in addition to 

 the rotation they already had as parts of the sun; there may have 

 been included some measure of vortex motion as most eruptions 

 generate such motion. There can be no question that practically 

 all the constituents of the outbursts were in the gaseous state as 

 they emerged from the sun and that they carried in to the sub- 

 sequent evolution the molecular activities common to hot gases. 

 The several projectile motions were more or less independently 

 imposed on the emerging mass, and later these underwent more or 

 less independent increases and declines, so that an important part 

 of the ensuing evolution consisted in their mutual adjustment to 

 one another. At the outset, the projectile velocity greatly pre- 

 ponderated over the velocities of all other motions, and until this 

 became adjusted so as to be approximately proportionate to all 



