486 



NATURE 



Sept 30, 1875 



measure ; it was of a black vitreous colour outside, and of a 

 greyish yellow inside ; it was then of a mouldy texture, 

 and hardened to the consistence of the present specimens 

 afterwards. 



" Only one stone fell. No rain had fallen for eight days pre- 

 viously, nor did it for four days after the fall of the stone. It had 

 been warm all day before, but not much more so than usual. From 

 mid-day till the time the stone fell (3 p.m.) it was very cloudy 

 towards the northward ; after its fall the thunder ceased, and the 

 clouds cleared away. No stone'of a similar description had ever 

 fallen near our village before. The pieces of the stone were im- 

 mediately after carried off by the country people. Our village is 

 situated on the banks of the small river, the Poorma. There are 

 no hills in its vicinity, the nearest being 3 coss (or 6 miles) off. " 



Finally, we may extract from the contemporary notices pub- 

 lished in the United States, the more remarkable circumstances 

 attending the fall of a great number of aerolites at New Concord, 

 U.S.A. :— 



" About fifteen minutes before one o'clock. May i, i860, the 

 people of South-eastern Ohio and North-eastern Virginia were 



startled by a loud noise The area over which the 



explosion was heard was probably not less than 1 50 miles in dia- 

 meter Anexaminationof all the different directions 



leads to the conclusion that the central point from which the 

 sound emanated was near the southern part of Noble County, 

 Ohio 



" Twenty- three distinct detonations were heard, after which the 

 sounds became blended together, and were compared to the rattling 

 fire of an awkward squad of soldiers, and by others to the roar of 

 a 'railway train. These sounds, with their reverberations, are 

 thought to have continued for two minutes. The last sounds 

 seemed to come from a point in the south-east, 45° below zenith. 

 The result of this cannonading was the falling ^of a large number 

 of stony meteorites upon an area of about ten miles long by three 

 wide. The sky was cloudy, but some of the stones were seen 

 first as 'black specs,' then as 'black birds,' and finally falling 

 to the ground. A few were picked up within twenty or thirty 

 minutes. The warmest was no warmer than if it had lain on the 

 ground exposed to the sun's rays. They penetrated the earth 

 from 2 ft. to 3 ft, The largest stone, which weighed 103 lbs., 

 struck the earth at the foot of a large oak tree, and after cutting 

 off two roots, one 5 in. in diameter, and grazing a third root, it 

 descended 2 ft. 10 in. into hard clay. This stone was found rest- 

 ing under a root which was not cut off. This would seemingly 

 imply that it entered the earth obliquely. It is said that other 

 stones which fell in soft ground entered the earth at a similar 

 angle. They must have been flying in a north-west direction. 

 This fact, added to the other facts, that the detonations heard at 

 New Concord came lower and lower from the zenith toward the 

 south-east, and that the area upon which the stones fell extends 

 with its longer axis in a south-east and north-west direction, 

 would imply that the orbit of the meteor, of which these stones 

 are fragments, extended from south-east to north-west. This 

 conclusion is confirmed by the many witnesses who saw at the 

 time a luminous body moving in the same direction. It is a fact 

 of some interest that the larger stones were carried by the orbital 

 force further than the small ones, and were found scattered upon 

 the north-west end of the area referred to. 



"Prof. Evans computes, from data supplied by several reliable 

 witnesses, the altitude of the meteor when first seen to range be- 

 tween thirty-seven and forty-four miles. 



" A train accompanying the stones is described as a cone, having 

 its base upon a fire-ball. As seen from near Parkersburg its 

 length was estimated at twelve times the diameter of the ball. 

 The part next the base appeared as a white flame, but not so 

 bright as to render the outline of the ball indistinct. About half 

 way toward the apex it faded into a steel blue. 



" Near McConnellsville several boys observed a huge stone 

 descend to the earth which they averred looked like a red ball, 

 leaving a line of smoke in its wake." McConnellsville is twenty- 

 five miles south of Concord. 



Another observer at Berlin saw a baH of fire flying in a 

 northerly direction with great velocity. It appeared as white as 

 melted iron, and left a bright streak .of fire behind it which soon 

 faded into a white vapour. This remained more than a minute, 

 when it became crooked and disappeared. Berlin is about 80 

 miles south-west of Concord. 



Now, these and other descriptions of similar events witnessed 

 by people in different parts of the world substantially agree. In 

 some minute circumstances they naturally differ, as doubtless do 

 also the events themselves or the conditions under which they 

 are witnessed. The appearance of a cloud at a great elevation, 

 its rapid motion, the emanation from it of masses of matter ulti- 

 mately falling to the earth, the association with these appearances 

 of a fiery light forming a splendid spectacle that lights up the 

 heavens by night and in twilight, and is often also seen by day ; 

 the trail that follows the great meteoroid mass, and lingers on 

 the air in the form of a long-drawn film of cloud that remains 

 luminous by night for some short period after the passage of the 

 luminous ball or cone, — are phenomena to which witness is borne 

 in many cases besides the last above recorded. Testimony is 

 also concurrent on the loudness and repetition of detonations 

 that accompany these phenomena, irrespectively of their multi- 

 plication by the effect of echo. In the case of a group of 

 meteorites that fell at Butsura, in India (near Goruckpore), on 

 May 12, 1861, we have evidence of three different explosions. 



Now, for some parts of the phenomena thus recorded we can 

 offer satisfactory explanations, though of other parts of them the 

 explanations hitherto offered may seem not quite so complete. 



First, we have the enormous velocity with which such a body 

 comes into our atmosphere, sufficient in some cases to bear the 

 meteorite through the distance from London to Edinburgh in as 

 many seconds as an express train takes hours ; and where the body 

 enters our atmosphere that medium is so rare that we can hardly 

 conceive it presenting any resistance ; yet even at that enormous 

 elevation — certainly in many cases as much as forty miles above 

 the earth, where the meteor enters this fine atmosphere — there 

 cannot be a doubt that the atmospheric resistance at once called 

 into play is sufficient to impede the body that enters it with 

 so enormous a velocity. And by virtue of a principle which is 

 now an axiom of science, this arresting of the velocity of the 

 meteorite means, calling into activity intense heat that is largely 

 imparted to the meteorite itself — heat, in fact, that is proportional 

 to the velocity for which it is exchanged. 



Now, these meteoric masses must often come into our atmo- 

 sphere, not individually, but in swarms. From the rapidity 

 with which the heat is developed, and partly also as a conse- 

 quence of the low conductivity for heat of the stony masses, their 

 surface only has time to experience the effects in the few seconds 

 of transit, and therefore only the surface fuses ; and, as a conse- 

 quence of this fusion, there arises a sort of spray of meteoric dust 

 flung off from the meteorite or from the meteoric swarm ; and 

 this forms a cloud, such as may be seen lingering on the 

 track of almost any large meteor that is visible by daylight. To 

 the material nature of such a cloud as it rests, or rather, 

 though rapidly falling, seems to rest, poised in the air, the 

 writer can bear personal testimony, having witnessed it in the 

 train of a fine meteor many years ago, about sunset. When the 

 ordinary clouds had long ceased to be tinted by the rays of the 

 evening sun, as in the after-glow on the Alps, the long line of 

 meteoric cloud became lit up with rose-tinted hues, and bending 

 into a curve towards the east before an upper current of air, offered 

 proof beyond question of the material nature of this cloud, and 

 at the same time of its great elevation and the fine state of 

 division of its dust-like particles, which undoubtedly resulted from 

 the disintegration of the meteoric mass in its passage through 

 the air. The same cloud of dust is often visible as a luminous 

 trail by night, in consequence partly of its retaining its incandes- 

 cence for a certain time, but probably also in part from the 

 phosphorescence of its material. We are thus able to offer an 

 undoubtedly true explanation of one part of the spectacle. 



The existence in the crust of a meteorite of projecting particles 

 of unoxidised meteoric iron, and, in the case of the Busti 

 meteorite, of calcium sulphide unaltered, is explained by the 

 momentary character of the process which during the flight of 

 the meteorite perpetually removes the outer surface and exposes 

 a fresh one, which, however, is always screened by a protecting 

 glaze of fused silicate from the immediate action of the air, so 

 long as there is velocity enough left to the mass thus to fuse 

 and to throw off" in its wake fresh portions of its surface ; while 

 in the later stage of its flight the glaze accumulates into a denser 

 crust highly charged with magnetic iron oxide, mainly the result of 

 the oxidation of the iron of the silicates. 



The cause or causes of the explosions are more difficult to de- 

 monstrate. They have been accounted for in two separate ways, 

 which, though different, are not inconsistent, and are both pro- 

 bably involved in a complete explanation of the disruption and 

 detonations. Why should a meteorite explode with a repor 



