380 CARNEGIE INSTITUTION OF WASHINGTON. 



in the ways above suggested. The disintegration of these gave rise 

 to meteorites. 



2. The second hypothesis assumes that solar gases and precipi- 

 tates were projected by forces of the kinds disclosed by the observa- 

 tions of Pettit on the solar prominences of May 29 and July 15, 1919,^ 

 into the outer regions of the sun's sphere of control, where solar attrac- 

 tion was feeble and the attractions of outer bodies relatively strong. 

 During this outer flight the pull of some star, group of stars, or outside 

 center of attraction drew the ejected matter aside from its path suffi- 

 ciently to cause it to swing by the sun on its return and take a highly 

 elliptical orbit. The plane of this orbit and the direction of revolu- 

 tion would be determined by the deviating attraction, so that a system 

 formed by a large number of such deviations would be very heteroge- 

 neous in orbital features, save that high ellipticity would be a common 

 characteristic. The principles of aggregation and lack of aggregation 

 herein previously sketched would apply to the projected matter in this 

 case. In so far as the projected matter retained self-control, it would 

 assemble by the precipitate-aggregate method into clouds or still more 

 concentrated bodies which by hypothesis would function as comet- 

 heads. These would be subject to all the vicissitudes of temperature 

 and of alternate absorption and evolution of gaseous material sketched 

 above and so function for a time as comets and ultimately be disinte- 

 grated into meteorites. In so far as the projected solar matter was too 

 highly dispersed for mutual control, it is assumed to have passed di- 

 rectly into meteoritic matter of the minutest type. Such minute 

 meteoritic matter abounds in interplanetary space in such prodigious 

 numbers that many millions are picked up daily by the earth. The 

 formation of precipitate-aggregates in the methods previously sketched 

 seems to furnish an apt explanation of the origin of chondrules and 

 other minute integers that so largely make up meteorites. The col- 

 lisions of these little bodies as they were entering into the formation of 

 larger bodies seems to account for the intimate brecciation, the little 

 specks of glass of singularly circumscribed extent — regarded as evidence 

 of suddenly cooled liquid spots — the strange mixtures of stony and 

 metallic matter, and other distinctive features. 



3. The third hypothesis is conditioned by the pre-existence of the 

 present planetary system. It supposes that in any given case the 

 ejected solar matter passed so near some one of the more massive 

 planets that it was thrown into an elliptical orbit in a way similar to 

 the preceding and with similar results. A certain portion of the mat- 

 ter so diverted would take orbits of the planetary type so far as their 

 planes are concerned, but only a part of these would have a planetoidal 

 degree of circularity. Other portions would have orbits whose eccen- 

 tricities, whose planes, and whose directions of revolution were as vari- 



lAstrophys. Jour.. 206-219, Oct. 1919. 



