230 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



contained jarred about as if shaken by an earthquake; in fact, many believed that an earthquake was in progress. 

 Quickly succeeding, and in fact blended with the explosions, came hollow bellowings and rattling sounds, mingled 

 with a clang and clash and roar that rolled slowly- southward as if a tornado of fearful power was retreating upon the 

 meteor's path. 



In September, 1875, an account was published by Hinrichs 5 as follows: 



On the evening of Friday, February 12, 1875, at 20 minutes past 10 o'clock, one of the most brilliant meteors of 

 modern times illumined the entire State of Iowa and adjacent parts of the States of Missouri, Illinois, Wisconsin, and 

 Minnesota. The southeastern portion of Iowa was bright as day, while the great meteor, in descending to the earth, 

 passed from Appanoose County to Iowa County. The meteor, in rapidly moving through the atmosphere, produced 

 a great variety of sounds rolling, rumbling, and detonations of fearful intensity which, in a large part of Iowa County, 

 shook the houses as if moved by an earthquake. 



But three days after the great phenomenon a meteoric stone weighing 7 pounds was found by Miss Sarah Sherlock 

 while on her way from school, precisely where observers had seen a ' ' glowing coal " descend to the earth. In April and 

 May, while the farmers were cultivating the land, about 400 pounds of meteoric stones were gathered on the meteorite 

 field of Iowa County. Quite recently two lajge meteorites have been found, aggregating 120 pounds. But these 500 

 pounds of meteoric stones are apparently only a portion of a smaller fragment of the entire meteoric body, so that the 

 whole mass falling to the earth, as the great Iowa meteor of February 12, 1875, must have weighed about 5,000 pounds. 

 Even what has been gathered thus far permits us to rank this meteor among the best observed and richest in meteorites 

 on record. 



********* 



The great Iowa meteor consisted of an elongated, pear-shaped mass of the most dazzling whiteness. The bulk of 

 this mass was about 2,000 feet long and 400 feet in diameter; the narrow white trail was about 4,000 feet long and 40 

 feet in diameter. This body was posteriorly enveloped by a much less brilliant trail, shading from orange inside to 

 greenish outside, and extending about 9 miles along the described path of the meteor. Persons in the track of the meteor 

 saw a brilliant circular disk of white light surrounded by an orange to greenish halo, the dim light of which was con- 

 stantly traversed by narrow bands of brilliant white, running from the central disk in irregularly curved lines toward 

 the circumference. As this body, increasing in brilliancy and apparent magnitude, was rapidly approaching, both 

 men and animals were overcome with fear. 



The meteor, when by striking the atmosphere of the earth it became visible , was at an altitude of 150 miles vertically 

 above the little village of Pleasantville, about midway between Kirksville and Milan, in northern Missouri. Descend- 

 ing at an angle of about 45 degrees toward the earth's surface, it moved a little east of north, gradually deviating more and 

 more toward the east so as to describe a curve, the concavity of which was turned eastward. This track of the meteor 

 passed a couple of miles east of Centerville and Moravia in Appanoose County, Iowa; almost directly over Eddyville on 

 the Des Moines River; crossed almost diagonally the northeastern (Prairie) township of Keokuk County; passed 1.5 miles 

 east of Marengo in Iowa County; and finally exploded over a point 3 miles southwest of the little station of Norway on 

 the Chicago & Northwestern Railroad, over the boundary line of Benton and Iowa Counties, at an altitude of about 10 

 miles. The total length of the orbit is 210 miles, through which the meteor passed in about 10 seconds, or at the rate of 

 21 miles per second. 



As the meteor crossed Prairie Township it was seen to divide into two unequal parts, a small eastern portion con- 

 tinuing its motion northeastward, but soon losing its brilliancy, and a seven to fourteen times greater western portion 

 which remained intensely brilliant until its final explosion. It was the smaller portion of the meteor which produced 

 the shower of meteorites in Iowa and Amana Townships of Iowa County; hence it is highly probable that several thousand 

 pounds of meteorites, some in pieces of over a hundred pounds, will yet be found east and north of the final explosion 

 of the main portion of the meteor ; that is, in Florence Township of Benton County, in Fairfax Township of Linn County, 

 and in Lenox Township of Iowa County. In fact observers saw " large glowing coals," as they described them, fall in 

 this region where Linn, Benton, and Iowa Counties meet. 



While dividing the meteor produced two tremendous detonations, and after the main body had crossed the railroad 

 at Marengo it produced three terrific detonations, which shook the buildings for miles around so as to produce the 

 impression of an earthquake. 



Besides these detonations the meteor was accompanied with a variety of other sounds, heard over a circular area of 

 150 miles in diameter. To those farthest away from the orbit it sounded as if their chimneys were on fire, and 

 astonishingly large number of persons missed the sight of the meteor because they hurried to their stoves and flues to 

 check the apparent fire. Those nearer the track heard a prolonged rumbling and rolling sound like that produced by 

 a train passing over a long, high trestle-bridge. Others still nearer the final explosion hurried upstairs, thinking the 

 plastering had fallen on the heads of their children sleeping in the upper story. Many in this same region heard the 

 clank and clatter of heavy, hard bodies striking against each other or against the hard ground. 



The meteorites thus far found occur in an elliptical area stretching from Amana von der Hohe, in Amana township, 

 to Boltonville, in Iowa township, a distance of 8 miles. The minor axis of this ellipse measures about 3 miles. The 

 entire meteorite field of Iowa County thus far covers, therefore, an area of 18 square miles. In the northwest the largest 

 pieces are found; toward the southeast the meteorites become gradually smaller. This agrees with their derivation 

 from the minor portion of the meteor. As the entire drift was eastward, the resistance of the air would, to some extent, 

 produce precisely this distribution of the meteorites, according to size. 



