STRUCTURE OF METEORITES MERRILL.. 185 



same conditions. Concerning these chondritic types, Sorby, as long 

 ago as 1866, expressed himself as follows : 



II. would, therefore, appear that, after the material of the meteorites was 

 melted, a considerable portion was broken up into small fragments, subse- 

 quently collected together, and more or less consolidated by mechanical and 

 chemical actions, among which must be classed a segregation of iron, either in 

 the metallic state or in combination with other substances. Apparently this 

 breaking up occun-ed in some cases when the melted matter had become crys- 

 talline, but in others the forms of the particles lead me to conclude that it 

 was broken up into detached globules whilst still melted (Mezo-Madaras, Par- 

 nallee). This seems to have been the origin of some of the round grains met 

 with in meteorites, for they occasionally still contain a considerable amount of 

 glass, and the crystals which have been formed in it are arranged in groups, 

 radiating from one or more points on the external surface, in such a manner 

 as to indicate that they were developed after the fragments had acquired their 

 present spheroidal shape. (Aussun, etc.) 



Tschermak, of Vienna, to whom is due some of the best of the 

 early work by modern methods, said, in describing the meteorite of 

 Orvinio, Italy : 



I regai'd the chondritic meteorites as attrition tuff's and the kugels of the 

 same as such rock particles as, owing to their toughness, have become rounded 

 rather than broken into splinters. 



The attrition, he thought, might have taken place in the chimneys 

 of volcanoes. Reusch, of Christiana, from a study of the Tysnes 

 stone, announced, in 1889, his belief that the typical chondrules are 

 but small rounded fragments, the form of which is due to external 

 causes and not to internal structure. He conceived the bronzito 

 kugels to have had originally a conical form, such as is sometimes 

 seen in radiating iron pyrites, the upper surface of the nodules form- 

 ing the base of the cone. "Wlien these become worn down by attrition, 

 the point breaks away, and hence in the section the radial point 

 always lies without the kugel. F. Rinne, writing as late as 1895, 

 compares the chondrules of meteorites to certain bodies observed by 

 him in the volcanic tuffs of Westphalia. These he describes as show- 

 ing a yellows-brown, glassy base with sharply defined "einspring- 

 lings" of olivine and monoclinic pyroxenes. These tuffs, however, 

 show gas cavities in this glassy ba,se, Avhile the meteorites do not. 

 The structure observed in the Kernouve meteorite, and which I have 

 referred to in that of Hendersonville, North Carolina, where larger 

 granules of silicate minerals are surrounded by finer, dustlike mate- 

 rial with no interlocking or true glassy base, he regards as a breccia 

 due to crushing and a partial refusion or a sintering, in this agreeing 

 with Tschermak. He claims to have produced similar forms by 

 sintering an olivine sand. 



My own views on the subject have undergone no material change 

 since expressed in an article by Dr. H. N. Stokes and myself in 1900, 

 when describing the meteorite of Allegan, Michigan, a somewhat 



