Dr. Walter Flight— History of Meteorites. 557 



1865, May 23rd.— Gopalpur, Bagerhaut, Jessore, India. 1 



In his paper communicated to the Vienna Academy Tschermak 

 gives the history of the fall of this stone, 2 from which it appears 

 that its descent was unattended by the detonation which usually 

 accompanies the descent of a meteorite. The stone, of which three 

 views are given in Tschermak's paper, has a greyish brown colour ; 

 when laid on the largest flat surface it has approximately a tra- 

 pezoidal boundary, the upper side being curved and exhibiting pits 

 and striped markings. The front surface (die Briistseite) is covered 

 with a thin feebly lustrous crust which is finely striped and chan- 

 nelled ; thee hannels have a radiate arrangement and converge to a 

 point near which is a small deep pit, while not far removed from it 

 is another deeper-lying hollow; all the pit-like depressions are 

 elongated, the extension being more marked the shallower they 

 become and the further they lie from the point of radiation. It will 

 be evident from this that during the transit of the meteorite through 

 the atmosphere this point was in front. (See the Tucson iron, page 

 499.) The heat generated by the compression of the air melts the 

 surface of the stone, and the attrition of particles of air with the 

 more porous portion of the front surface forms the depressions 

 radiating from the foremost point ; the fused drops as fast as formed 

 are driven off by the opposing air and give rise to the fine radiated 

 texture of the crust. The hinder surface has very different characters : 

 it consists of two almost flat faces meeting 'nearly at right angles 

 and forming sharp edges with the front surface. Along this edge 

 the very distinctive crust of the front surface slightly overlaps the 

 hinder portion, terminating in a well-defined and sometimes fringed 

 border. Here the crust is verrucose, most of the granules consist- 

 ing of fused matter, many enclosing unaltered grains of the meteorite; 

 few follow the radiated arrangement observed in the former case. 



As regards the structure of the stone of Gopalpur it closely re- 

 sembles, in the diminutive size of its chondra, the meteorites of Pegu 

 and Utrecht. They are of three kinds : 1). The most striking have 

 a brownish-grey hue and fibrous fracture, their optical principal 

 sections being parallel and perpendicular to the direction of the 

 fibres; these appear to be bronzite; 2). The next have a radiate 

 structure, and are built up of larger bar-like transparent crystals, 

 which in one spherule were observed to radiate from two centres ; 

 these are not improbably a felspar ; and 3). The last kind of chondra 

 consist of a granular fissured mineral which appears to be olivine. 



The spherules have the same composition as their matrix, bronzite, 

 olivine, nickel-iron and magnetic pyrites forming the predominating 

 constituents in each case. While the chondra, met with in terrestrial 

 rocks, in perlite, obsidian, pitchstone, in many diorites, are radiate- 

 fibrous, those occurring in meteorites are but rarely so, and in these 

 cases the arrangement of the fibres within the spherule is excentric. 

 Moreover, while the meteoric chondra, as already stated, consist of 



1 Gr. Tscliermak. Sitzber. Ahad. Wiss. Wien, 1872, lxv. 135. Mineralogische 

 Mittheilungen, 1872, 95. — A. Exner. Mineralogische Mittheihtngen, 1872, 41. 



2 Proc. Asiat. Soc. Bengal, 1865, 94. 



DECADE II. — VOL. II. — NO. XI. 36 



