Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Frontispiece. George Perkins Merrill. Plate 1. External form of Allegan and Bath Furnace stones; and of Mazapil Iron. 2. (1) Carbon nodule in Canon Diablo meteoric iron; (2) Re-fused feld spar in Estherville meteoric stony iron. 3. (1) Maskelynite in Troup meteoric stone; (2) Merrillite in New Con cord meteoric stone. 4. (1) Fragmental twinned pyroxenes in Johnstown meteorite; (2) Frag mental pyroxenes in Estherville meteorite. 5. (1) Widmanstatten figures, enlarged; (2) Schreibersite in Arispe and (lower) in Tombigbee irons. 6. (l) Meteoric iron from Dungannon, Va., showing partial granulation; (2) The same greatly enlarged. 7. (upper) Swathing kamacite in Admire pallasite; (lower) Octahedral structure and Reichenbachian lines in Carleton iron. 8. (upper) Neuman lines in Braunau iron; (lower) Granular structure in Mejillones iron. 9. (upper) Octahedral iron with silicate inclosures, Four Corners, N. Mex.; (lower) Persimmon Creek, N. Iron.