128 Field Columbian Museum — -Geology, Vol. III. 



■ of a greenish-gray color and firmly coherent texture so that it takes a 

 good polish. Enough weathering has taken place, however, to give 

 the interior in large part a dark-brown color. The percentage of 

 metallic grains seen on a polished surface is large, so as to seemingly 

 constitute about one-fourth the mass. The metal is uniformly dis- 

 tributed but the grains vary in size and shape. Some having a diameter 

 of 4-5 mm. are discernible. At times they aggregate into vein-like lines. 

 Both polished and unpolished sections show the interior of the meteor- 

 ite to be penetrated by a great number of minute fissures arising prob- 

 ably from hydration. Most of them contain carbonate of lime which 

 has doubtless been brought in by infiltrating waters. Such fissures, 

 as well as the metallic "veins" are shown in an illustration published 

 in the Museum Catalogue of Meteorites of 1903.* Under the micro- 

 scope all the striking characters of the spherical chondrites are pre- 

 sented by the meteorite. Chondri of great variety of size and struc- 

 ture make up the principal mass. For the most part the chondri are 

 spherical in form but some are oval and others of unsymmetrical out- 

 line. Besides complete chondri, fragments of chondri are to be seen. 

 As was stated in the writer's first paper on the meteorite, enstatite and 

 olivine either singly or in combination chiefly compose the chondri. 

 Diameters of from .3 -.6 mm. are presented as a rule by the enstatite 

 chondri, but one 3 mm. in diameter was seen in one section. Several 

 of the half-glassy chondri show rounded depressions as if made by 

 the pressure of another chondrus. The olivine chondri are both mono- 

 somatic and poly somatic, also porphyritic and lamellar. In dimen- 

 tion they vary as widely as do the enstatite chondri and between about 

 she same limits. The porphyritic individuals of the chondri show, 

 as a rule, well-marked prismatic outlines. Crust sections under the 

 microscope fail to show, except for an outer fusion zone, well marked 

 zones such as are common in the more porous chondrites. The fusion 

 zone is of a dark, nearly opaque, somewhat blebby and glassy nature 

 and has a thickness of about .08 mm. Succeeding this, towards the 

 interior of the meteorite, a zone about .4 mm. in thickness shows scat- 

 tered opaque impregnations interspersed among unaltered olivine 

 crystals. This zone is not uniform in occurrence, however, and can 

 be seen only at intervals. 



WHSTON. 



In connection with the meteorite fall which occurred at Weston, 

 Connecticut, December 14, 1807, a well-marked distribution of the 

 masses according to weight took place to which attention does not 

 * Pubs. Field Col. Mus. Geol. ser. Vol. II, PI. XXXI. 



