492 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. XIII. 



these cavities had their widest extension or opening toward the apex of the cone. Nothing can be clearer than that 

 this was produced by the tremendous friction of the densely compressed air through which the meteorite passed on 

 its way to earth. 



The air, which was compressed in front of the mass to a density comparable to that of some solid substance, has 

 flown back past the apex and the sides o the cone' with a friction force almost inconceivable in its intensity. The 

 air crowded in front of a meteorite having a velocity of 60 miles per second has furthermore been shown by physicists 

 to have, by reason of its compression, a heat of over 5,000 Centigrade (9,000 Fahr.), a heat calculated to melt away 

 any surface which it enveloped. It is to the melting, rubbing, and chiseling effect of this compressed air, with its 

 following air stream, that we may attribute all the glazing, pitting, hollowing, and channeling which has been 

 observed on the front side of the cone and upon the flaring base of the great meteorite. That the melting should be 

 more complete on the forward part of the cone is easily conceivable. Also, it is clear that the boring and channeling 

 power of the air should be -most exercised on the basal flanges, on which it more directly impinged. The effects are 

 colossal, and words but feebly express the impression made by the eight of the great cone, with its torn, excavated 

 sides. It seems impossible in theory, but the whole is made easily credible in seeing and studying the effect. 



It is probable that this mass contained great nodules or even long cylindrical inclusions of some mineral softer 

 and more subject to attrition than is the iron of which it seems to be wholly composed. These inclusions may have 

 determined the position and greatly enlarged the size of these excavations. This is particularly true of the long fur- 

 rows. In these, the upper part of the wall hangs over as a rim, leaving the tube or gutter, as seen from the side, 

 larger within than in its outside exposure. These furrows, as well as one of the holes, gouge deep recesses out of the 

 otherwise continuous border of the mass. The lower part of the cone rolls smoothly around to join its base. 



The original surface of the base was slightly crowning; was covered with well-developed normal pittings of great 

 similarity of character in all parts. The remaining areas of this surface are in every case thus covered. Further- 

 more, we observe the striking manner in which the base of the mass was drilled and bored by the clean round holes. 

 Counting only those that are of limited diameter, there are over 30, varying from 0.5 to 2.5 inches across, and from 

 3 or 4 inches to an unmeasurable depth. Indeed, quite a few of them which are near the periphery, pass completely 

 through the mass. One of these perforating vertical bores or drill holes is seen at the base of the figures; the other 

 two are visible toward the extreme left. The position of these upon the base, the re^r side of the meteorite, argues 

 strongly for their origin from preexisting cylindroid nodules of troilite. The inner trend of some of these bores is quite 

 irregular, and the surface roughened with sharp tortuous ridges. Some few of the holes join each other below, anasto- 

 mosing as may sometimes be seen in sections of long troilite nodules in the face of a section of siderite. In the fre- 

 quency of these long round holes and their general distribution over all sides of the mass, the present meteorite resem- 

 bles, though it surpasses, Canon Diablo. 



But attention is strongly drawn away from these aerial features to a most singular and astonishing group of con- 

 cavities and caverns. Nothing can exceed the labryinthine and chaotic outspread of these. They cross the mass 

 from side to side and from end to end. Yet they have no regularity of distribution or system of alignment. They 

 make a confusion of kettle holes, washbowls, or small bathtubs. One of the latter, crossing the mass diagonally is 

 3 feet long by 10 to 15 inches across and of an average depth of 16 inches. Another, nearly circular, is 2 feet in 

 diameter and 18 inches in deepest part. This one is quadrifid in its bottom; each of the four areas being a distinct 

 basin, swelling gently up from its center to the sharp crest running between it and its neighbors. To describe these 

 caverns individually would be impracticable as well as useless. This extraordinary meteoritic phenomenon is evi- 

 dently produced by decomposition due to the action of water. They are not the product of erosion as are the deep 

 holes and channels of the other side of the mass. There are here no lines of flow, no connections in the nature or trend 

 of the depressions. It has been noted that this meteorite lay in its original bed, as it fell, with the conical end down, 

 and the flat base upward and quite level; that it lay just below the surface of the ground in a soil charged throughout 

 with vegetable matter, the accumulation of centuries under the falling leaves and branches of a primeval forest. 

 Moreover, western Oregon is a region marked as a rain belt ever since its first exploration. Every condition was ful- 

 filled for the decomposition of this great mass of iron, so situated that its surface was always soaked with water heavily 

 charged with carbonic acid, due to vegetable decomposition. Under such conditions the oxidation of the mass would 

 go on rapidly. The depressions would soon be initiated; these would fill with water, and thenceforth the dissolution 

 of the mass would proceed rapidly with ever increasing area and rapidity. This action would never be intermitted 

 or minimized ; for while the frosts of the short winter may have materially lessened the chemical action for a time 

 each year, the increased mechanical effects of freezing and thawing would quite compensate for this diminution of 

 the destructive work. It is especially noticeable in studying these caverns that certain portions of the surface of the 

 mass are entirely without them, holding today not only the original superficial level, but also retaining in fullest 

 degree the pittings and all other markings which the mass showed when it fell. These areas of original surface stand 

 as islands in the waste depressions produced by the process of decomposition; and in the majority of cases these inter- 

 vening areas have been undermined by the same process which produced the caverns. The projecting portion of 

 these areas are frequently penetrated by the noticeable borings already described. Again, the intervening walls 

 between the caverns have been eaten through in at least 10 places, leaving large irregular openings between the 

 large excavations. These basins or caverns have a rough, sandy surface, not to be compared with the smooth semi- 

 polished inner wall of the holes bored by the friction of the atmosphere. The difference is as evident, and somewhat 

 the same, as that between a glaciated rock and a sawed or ground rock surface. Here is again occasion for the sup- 

 position that these excavations are in some measure due to the presence of a softer and more easily decomposed 



