The remarkable cratcriform pit in central Arizona, famous on account of its association with the Canyon Diablo siderites and through the writings of Dr G. K. Gilbert, has lately come into special geologic interest through the explorations of the Standard Iron company. Appreciating the money value of the rare elements associated with a large quantity of meteoric iron and believing that an enormous mass was imbedded in the crater, four men with commendable enterprise and scientific interest, backed by financial ability, acquired the crater and adjacent land under mining law, and for four years have been probing the crater and its rim. Recently two of the company, Mr. D. M. Barringer and B. C. Tilghman, have published articles giving the results, to that date, of their explorations.†
Up to the present time more than 50 pits and trenches have been excavated in the debris of the outer slopes; seven . . .