294 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



It is said that three more of the stones have been found, all of which are precisely similar in appearance and nearly 

 of the same weight as this one before it was broken. 



The explosion was heard distinctly by one of the surveyors who was engaged on the survey of the public lands 40 

 miles distant from Mr. Rogers's house. 



A more complete description of the meteorite was given later by Shepard 3 as follows: 



The small stone seen to fall was picked up on the land of Mr. Daniel C. Rogers, situated on sec. 21, T. 82 N., 

 R. 6 W. The larger portion of the fallen meteor was found in section 2^), from 1 to 1.5 miles west. This consisted of 

 two masses and not, as at first supposed, of two fragments of a single stone. The larger of the two (whose weight was 

 estimated at above 40 pounds) was cracked through the center by its fall upon the frozen ground. One of these halves 

 (weighing 21 pounds 7 ounces) is in my possession. The smaller perfect stone is represented by the finder as pyramidal 

 in shape and measuring 10 inches in length, by 8 at its base, and 4 at the smaller extremity. It was completely coated 

 by a black crust, like the other two stones. This stone, as well as one-half the larger mass, has been broken up, and 

 for the most part entirely lost. The few fragments of it in existence show that it differs scarcely at all from the 

 other two. 



The smaller of these two may be best described by comparing it to a short rectangular prism (the longer side measur- 

 ing 4 inches, the shorter 2.5 inches) surmounted at one extremity by a four-sided pyramid of unequal and much-curved 

 faces, and terminated at the opposite end by an oblique, waving plane, upon which the stone is conveniently set up 

 When in this position the apex of the pyramid is 3.5 inches from the base. The angles and edges of the mass, as is usual 

 in such bodies, are rounded and blunt. It has but few depresswns in its surface. The crust is perfect in its continuity 

 and is smooth and black, though not shining The stone weighs 2 pounds 8$ ounces. 



The large mass (of 21 pounds 7 ounces) is an irregularly shaped, four-sided pyramid, the summit of which is an edge 

 of 4 or 5 inches in length. The base of the pyramid is formed by the fractured surface, which is nearly plane, and 

 strikingly resembles the fracture of fine-grained granite. 



The natural outside of the stone presents the customary depressions, though less distinct than is usual. The crust 

 is similar to that of the small stone already described, only thicker than common (being of the thickness of bonnet 

 board), its adhesion to the unaltered stone strong, while its line of junction with the same is perfectly defined throughout. 

 When narrowly observed it is discovered that the surface of this crust is divided off by cracks into polygonal areas of 

 from 0.25 to 0.5 inch in diameter, in consequence no doubt of sudden cooling. 



The color of the stone within is a uniform pearl gray. A closer inspection reveals specks of iron rust, though less 

 abundant than common, and numerous highly brilliant globules of nickeliferous iron. It requires a still nearer search 

 to detect the magnetic pyrites, which is far less abundant than the metallic grains. Blackish grains and glazed joints 

 are nearly obsolete in the Iowa stones. The same may be said of the little ovoid masses, which are also so frequent in 

 most other stones. 



Its most remarkable feature, however, consists in the homogeneousness of its earthy composition. It appears to 

 contain but a single mineral species of this description and this is one which, though perhaps the most common in 

 other meteoric stones, has until now escaped a separate recognition. I have therefore ventured to bestow upon it a 

 distinct name, that of howardite, in honor of an early scientific laborer in this branch of meteorology who ranks next in 

 importance to Chladni himself. 



The proportions of the ingredients in this stone approach the following: 



Howardite 83.00 



Nickel iron 10. 44 



Magnetic pyrites 5. 00 



Olivinoid and anorthite... . trace 



98.44 



Omitting the pyrites, the composition of the mineral may be stated thus: Oxygen ratio. 



Silicicacid '. . . . 63.06 31.53 3 



Protoxide of iron 24. 60 5. 461 



Magnesia 11.74 4.70) 



Soda and potassa 31 



99. 71 



It is therefore a tersilicate of protoxide of iron and magnesia, Fe Si+Mg Si. 



The composition of the nickel iron approaches very closely to 



Fe 86.0& 



Ni 14.00 



a peculiar alloy which appears to be very common in meteor masses. 



Another large stone of this same fall, weighing 20 pounds, was described by Shepard/ He 

 says: 



The following statement concerning it is from a letter of Rev. R. Gaylord, of Hartford, Iowa, dated July 3, 1850. 

 "It was found (in the summer of 1847) in Hooshier Grove by Abner Cox. He was in company with John Hollis, of whom 



