292 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



MADOC. 



Madoc township, Hastings County, Ontario. 



Latitude 45 31' N., longitude 73 35' W. 



Iron. Fine octahedrite (Of) of Brezina; Madocite (type 10) of Meunier. 



Found, 1854; described, 1855. 



Weight, 167.5 kgs. (370 Ibs.). 



The first mention of this meteorite was by Hunt, 1 as follows : 



A large mass of native iron was found last autumn upon the surface of the earth in the township of Madoc, Ontario; 

 it has since been procured by Mr. Logan, the director of the Geological Survey, in the collection of which it has been 

 placed. The mass is rudely rectangular And flattened, but very irregular in shape; its surface is deeply marked by 

 rounded depressions which are lined with a film of oxide. It closely resembles in appearance the Lockport, New 

 York, iron, with which it seems to agree in composition; a single analysis gave 6.35 per cent nickel, in which no cobalt 

 was detected. The iron is very soft and malleable, and from a trial with a small fragment exhibits a coarsely crystal- 

 line structure; the weight of the mass is 370 pounds. We purpose to have it cut, and I shall then be able to make a 

 more complete examination of the iron. 



The history and characters of the meteorite have been further given by Cohen, 6 as follows : 



Reichenbach 2 described Madoc as containing kamacite, taenite, and plessite; the latter was quite dark and full 

 of combs. He also mentioned grains of bronze-colored iron sulphide with inclusions of numerous needles and with 

 an envelope of taenite and a coating of rust with specks of iron glass. 



Brezina 3 gave the following charactersitics: " Bands long, closely compacted together, hatched, 0.3 mm. in width, 

 granulated; bands and combs few." 



Meunier * made of Madoc a new type, viz, madocite. According to him nodular plessite strongly predomiuates, 

 taenite is present in fine, often slightly regular scales, and kamacite is extremely scarce; schreibersite occurs in rods 

 somewhat resembling those of Magura. 



The section examined by me shows long, sometimes straight, sometimes bent, occasionally much compacted, 

 granular bands, inconspicuous taenite seams, and numerous fields which are inconspicuous in comparison with the 

 bands; the former do not show up very distinctly, since in comparison with the bands in respect of color and luster 

 there is no marked distinction. The kamacite is somewhat speckled in places and shows many distinct file marks 

 accompanied with comparatively large etching pits. It has also a satiny oriented luster of considerable brightness. 

 The plessite is composed principally of sometimes approximately isometric and sometimes elongated grains measur- 

 ing 0.05 to 0.20 mm. in thickness, which are sharply separated from one another by dark deep grooves; in some fields 

 the grains are elongated to granular rods measuring 0.25 to 0.4 mm. in thickness and of slightly regular form. It is 

 characteristic of this plessite that it is appearently free from tsenite or scales resembling tsenite. Fields with dark 

 compact plessite and almost microscopic in size occur only occasionally and then only in entire isolation, so that 

 the absence of such fields to the unaided eye may be regarded as characteristic. Minor constituents seem to be very 

 scarce, but troilite, schreibersite, and iron glass were observed. 



Madoc has a very prominent alteration zone of varying breadth. The boundaries of the lamellae in it can be readily 

 distinguished, but the structure of the kamacite is sometimes speckled and sometimes decidedly granular. The color 

 of the etching surface is darker and the luster duller in this zone. 



The meteorite is chiefly preserved in the Museum of the Canadian Geological Survey, 

 Ottawa, Canada. Small sections are distributed. 



BIBLIOGRAPHY. 



1. 1855: HUNT. On a newly discovered meteoric iron. Amer. Journ. Sci., 2d ser., vol. 19, p. 417. 



2. 1858-1862: VON REICHENBACH. No. 4, p. 638; No. 6, p. 448; No. 7, pp. 552, 561; No. 9, pp. 163, 174, 181; No. 12, 



p. 457; No. 15, pp. 110, 114, 124, 126; No. 16, pp. 250, 261, 262; No. 17, pp. 266, 272; No. 18, pp. 480, 487; No. 

 19, p. 150; No. 20, p. 622; No. 21, 589. 



3. 1885: BREZINA. Wiener Sammlung, p. 210. 



4. 1893: MEUNIER. Revision des fers me'te'oriques, pp. 39-40. 



5. 1905: COHEN. Meteorintenkunde, Heft 3, pp. 354-356. 







Marengo. See Homestead. 



MARIAVTLLE. 



Rock County, Nebraska. 



Latitude 42 45' N., longicude 99 25' W. 



Iron. 



Fell? October 16, 1898, between 12 and 1 a. m. 



Weight, 34Q grams (12 ounces). 



Our only knowledge of this meteorite is a brief note by Barbour, 1 who stated that the 

 finder said it had fallen in Maria ville, Rock County, Nebraska, between 12 and 1 o'clock on the 



