2IO 
The American Geologist. October, 1902. 
weights based on simple guessing may diffe/ from proven 
weights is well illustrated by the case of Chupaderos, one of 
the meteorites just cited. Fletcher, the noted mineralogist 
of the British Museum, says of it, "According to one recent 
estimate its weight is 15 tons, according to another it is 82 
tons." Anighito, the great Greenland meteorite, has been 
guessed at all figures from 30 to 100 "tons. A late unofficial 
estimate of it, after careful measuring, puts its weight at 46 
1-3 tons. 
Should the ]\Iexican government, as we sor<ie expect, move 
the great mass, as it has done all the. others, to the capital, 
its exact weight will be finalfy and definitely known. 
Whichever mass shall, after accurate calculation, prove 
to be the heavier, it will ever remain of interest that the two 
largest meteorites known to our earth shall hj:ve fallen on the 
North American continent, one far toward its northern end, 
the other toward its southern. 
The inner structure of this meteorite is interesting as 
showing the octahedral system of crystallization in a very 
marked degree. We know of no other meteoric iron which 
shows this equally, unless it be that of the Sevier Co., Tennessee, 
or San Angelo, Texas. Fractional surfaces show crystallization 
plates with faces from 3 to 19 mm. in greatest diameter. 
Many of these faces are covered with fine films of taenite, 
which in most cases are of the characteristic bronze yellow 
color. Acid brings out the Widmanstatten figures in a 
beautiful manner. From the coarse crystals on a frac- 
tured or a weathered face of this iron, we might anti- 
cipate that etching would reveal a large, wide pattern in 
its markings. As a fact quite the converse is true. The fig- 
ures, while very sharp and clear are small in pattern and are 
composed of narrow blades of kamacite which are but a frac- 
tion of a millimetre in diameter. At intervals, these blades 
appear to be of more than double that thickness ; but when 
examined with a glass it is seen that these ap^Darently broader 
plates are composed of what might be expressed as bundles 
of the narrow kamacite bands. The rhombic figures on the 
etched face will average from lYi to 5 mm. in diameter, 
the two angles of the same being 60° and 120°, while the tri- 
angular markings will generally range from 8 to 15 mm. with 
