AVARD — BACUBIRITO. 73 



Chupaderos (Mexico), 15^3 tons. 

 Anighito (Greenland), 50 tons. 

 Bacubirito (Mexico), 50 tons. 



The former three are weights proven on scales. The latter two 

 are thus far simple estimates. How far estimated weights, based on 

 simple guessing, may differ 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 w^eight 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 unolificial estimate 

 of it, after careful measuring, puts its weight at 46^ tons. 



Should the Mexican Government, as we some expect, move the 

 great mass, as it has done all the others, to the capital, its exact 

 weight will be finally 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 

 have 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 Sevier Co. , Tennessee, or San Angelo, Texas. 



Fractured 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 Widmanstiitten figures in a 

 most beautiful manner. From the coarse crystals on a fractured or a 

 weathered face of this iron, we might anticipate that etching would 

 reyeal a large, wide pattern in its markings. As a fact, quite the con- 

 verse is true. The figures, while very sharp and clear, are small in 

 pattern and are composed of narrow blades of kamacite, which are 

 but a fraction of a mm. 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 apparently 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 i^ to 5 

 mm. in diameter, the two angles of same being 60° and 120°, while 

 the triangular markings will generally range from 8 to 15 mm. with 

 angles of 55°; 55° and 70°. Troilitesare particularly scarce, but two or 

 three small ones having shown on any of the sections made. The 



