920 IRON 



9. Is a more recent analysis of the same. 10. From Lockport in North America. 

 11. From Bitburg, near Trcves, which weighed above 3,300 Ibs. 



According to Shepard (' Silliman's American Journal '), the fall of meteoric stones 

 is confined principally to two zones. The one, belonging to America, lies between 33 

 and 44 N. lat., and is about 25 in length. Its direction is more or less from N.E. 

 to S.W., following the general line of the Atlantic coast. Of all the occurrences of 

 this phenomenon during the last 50 years, 92'8 per cent, have taken place within 

 these limits, and mostly in the neighbourhood of the sea. The zone of the eastern 

 continent, with the exception that it extends 10 further to the north, is bounded by 

 the same degrees of latitude, and follows a similar north-east direction ; but it has 

 more than twice the length of the American zone. Of the observed falls of aerolites, 

 90'9 per cent, occurred within this area, and were also concentrated in that half of 

 the zone which extends along the Atlantic. 



Amongst the remarkable masses of meteoric iron the following must be named : 

 that found by Don Rubin de Celis, in Tucnman in South America in 1783, weighing 

 300 cwts. ; that discovered in 1784 on the Riacho de Bendego in Brazil, estimated to 

 measure 32 cubic feet, and to weigh 17.300 Ibs. ; and that on the Red River in 

 Louisiana, weighing above 3,000 Ibs., and presenting distinct octahedral crystals. 



The Swedish expedition to Greenland discovered some enormous masses of meteoric 

 iron in 1870, and in 1871 it brought back twenty specimens, amongst which were two 

 of enormous size ; the largest, weighing more than 49,000 Swedish pounds, or about 

 21 tons English, with a maximum sectional area of 42 square feet, is now placed in 

 the hall of the Royal Academy of Stockholm ; whilst, as a compliment to Denmark, 

 on whoso territory they were found, the second largest, weighing 20,000 Ibs., or about 

 9 tons, has been presented to the museum of Copenhagen. Chemical analyses of these 

 remarkable masses have proved them to contain nearly 5 per cent, of nickel, with 

 from 1 to 2 per cent, of carbon, and to be quite identical with many aerolites of known 

 meteoric origin. These masses were discovered lying loose on the shore, but im- 

 mediately resting upon basaltic rocks, in which they appear to have been originally 

 imbedded. Professor Nordenskjold and several others familiar with meteoric irons 

 consider these masses to be meteorites. See AEROLITES. 



Franklinite. This ore of iron usually crystallises in octahedra, but is also found 

 massive. According to Rammelsberg, it consists of iron 45*16, manganese 9'38, zinc 

 20'30, oxygen 25*16. It is said to occur in amorphous masses at Altenberg, near 

 Aix-la-Chapelle, but it is found abundantly at Hamburgh, New Jersey, where it 

 occurs in a metamorphic Silurian limestone with red oxide of zinc and garnet. It is 

 also found at Stirling Hill in the same locality, where it is associated with Willemitc 

 in a large vein, in which cavities occasionally contain crystals from 1 to 4 inches 

 diameter. The attempts to use this ore have not been very successful. Dana says 

 it is ground up and used for a dark paint, and some of it has been smelted for iron, 

 to which the zinc is thought to give tenacity. The zinc has also been separated and 

 the residues smelted for spiegeleisen. See FRANKLINITE. . 



Magnetite, Magnetic Iron Ore, Native Loadstone, or Octahedral Iran Ore. This 

 very rich and valuable ore occurs especially in igneous or metamorphic rocks, either 

 in distinct crystals, or, as in many .basalts, disseminated through the mass, when it 

 frequently imparts magnetic properties to the rocks, especially to greenstone, serpentine 

 and basalt. It also forms beds in gneiss, in chlorite-, mica-, hornblende-, and play-slates, 

 in marble, greenstone, and other rocks, but seldom appears in veins. The largest 

 known masses occur in the northern parts of the globe, in Scandinavia, Lnpland, 

 Siberia, and North America. Less extensive masses occur in the Hartz, in Saxony, 

 Bohemia, Silesia, and Styria; and in Southern Europe, in Elba and Spain. Magnetite is 

 the most important ore of iron in Norway, Sweden, and Russia. The Dannemora mines 

 in Sweden, wrought in an open quarry 150 feet broad, and 500 feet deep, furnish the 

 fine Oeregrund iron, largely imported into England for the manufacture of steel. 

 Some highly magnetic varieties, especially from Siberia and the Hartz, form natural 

 magnets, possessing distinct polarity. Others become polar only after contact with 

 magnets of sufficient power. Magnetic iron ore is found in rather considerable masses 

 not far from Haytor on Dartmoor, and near the village of Brent, at the southern 

 extremity of Dartmoor. It is also found in Cornwall, in the vicinity of the Indian 

 Queens ; near Penryn, Ponsanooth, and a few other localities. Magnetic iron ore 

 fuses with extreme difficulty; it is not acted upon by nitric acid, but when powdered 

 is soluble in hydrochloric ; its specific gravity varies from 4*24 to 5*4. The chemical 

 formula of pure magnetite is FcO.I'VO 3 , corresponding to 31*03 of protoxide, and 

 6877 of peroxide of iron, or of 7- M) in.n. and 27'60 oxygen, which agn i-s c!<> !y 

 with the analyses of Berzelius, Kobell, and Karsten. 



Analyses I. and II. are of magnetic iron ore from Cornwall by Noad ; III. of Dan- 

 nemora magnetite by Ward : 



