258 AJsnsruAL report Smithsonian institution, 1942 



period of the earth's rotation. Such swarms would have remained 

 approximately above the Pacific basin, but would have gradually 

 fallen behind and tended to be drawn to the earth on account of per- 

 turbations resulting from the gradual retardation of the moon. 

 Cumulative perturbations and other related factors have caused 

 swarms of these bodies to come down to the earth at widely separated 

 geologic periods in the earth's history, such falls having been par- 

 ticularly extensive along a great-circle route crossing the western 

 edge of the Pacific basin. This condition would account for the 

 great quantity and wide distribution of the Indo-Malaysian tektites 

 especially, which are of almost identical chemical composition, while 

 other showers of tektites came at different geologic periods and varied 

 somewhat in composition and physical appearance. 



While final critical appraisal of the theory must come from others 

 better grounded in astronomical and geophysical knowledge than the 

 present writer, there are certain implications of this new hypothesis 

 that may well be pointed out. First, negatively, the well-known 

 chemical differences between the true tektites and known earthly 

 rocks have not yet been satisfactorily accounted for. It is true, per- 

 haps that there are very few analyses of deep-seated glassy basalts 

 available in our literature, and that this fact might account for the 

 j)rincipal difference observed between the tektite chemical pattern and 

 that of the more widely known surface rocks (either plutonic or vol- 

 canic) . In particular the dominance of potash over soda in the tektites 

 is outstanding, and is accompanied usually by a predominance of 

 ferrous oxide. This condition is just the opposite of that of most 

 known earthly rocks and glasses, and it is obvious that further evidence 

 is needed here. 



It should be noted, however, that the f oreging objection applies with 

 equal force to all other proposed tektite theories, except the generalized 

 cosmic hypothesis. On the other hand, the Rufus theory explains or 

 lends important support to a number of other views hitherto regarded 

 as not altogether acceptable in their entirety ; e. g., Fenner's views as 

 to the origin of the secondary forms of the Australites fit in very well 

 with the Rufus theory ; in fact the Australites furnish probably the 

 best support for the new theory, although they almost certainly repre- 

 sent a different shower from that which gave us the Indo-Malaysian 

 tektites. The larger and heavier Indo-Malaysian tektites would have 

 been drawn down at an earlier period than the smaller and lighter 

 Australites, although the glassy substance of which both are formed 

 is of almost identical chemical composition. 



Past experience has shown that it is easier to demolish tektite theories 

 than to find substantial support for any one of them,. Professor 

 Rufus has thus been rightly cautious in presenting his new explana- 

 tion, and in welcoming expected criticism and discussion. It is 



