January 27, 19 16] 



NATURE 



595 



of the scientific investigator, but of the medieval 

 theologian appealing to the emotions in defence of 

 >nine dogma which is indefensible by reason. 



G. Elliot Smith. 

 The Univ-ersitv, Manchester. 



The Board of Education and Laboratory Work: 

 A Correction. 



On p. 548 of Nature (January 13) I stated that the 

 Board of Education had suggested the substitution of 

 lecture-demonstrations for laboratory work in schools. 

 I have been informed that the apparently trustworthy 

 information on which I relied was incorrect. It is 

 satisfactory to be able to state authoritatively that the 

 Board has made no such suggestion, nor was the 

 Board responsible for the recent adoption of this form 

 of retrenchment in certain schools. 



G. F. Daniell. 



.4 TERRESTRIAL CRATER OF THE 

 LUNAR TYPE.^ 



ALTHOUGH the memoir before us was read 

 before the U.S. National Academy of 

 Sciences so far back as six years ago, it has only 



stone (carboniferous), and 1000ft. of white sand- 

 stone. Although these beds underlying the 

 " butte " have been explored by numerous borings, 

 neither in the strata themselves nor in the dark 

 red sandstone rocks below them has the smallest 

 indication of volcanic materials been met with ; 

 neither has the faintest trace of solfataric or other 

 ''volcanic action been detected. The nearest scene 

 of volcanic activity is found on a small scale 

 nine miles away, and on a grander scale 40 miles 

 farther. On the other hand, fragments of the 

 famous " Canyon Diablo meteorite " (which con- 

 tains diamonds with platinum and iridium) have 

 been found in countless numbers in and around 

 the "butte," and up to a distance of five miles 

 around it. 



The "crater" of Coon Butte is a depression, 

 circular in form and about 4000 ft. in diameter, 

 with a rim that rises 570 ft. above a floor, which 

 is quite level except where obscured by talus from 

 the rim. In this rim the limestone and sandstone 

 rocks are seen to have undergone the most violent 

 disturbance; they dip away from the centre at 

 various angles up to 90°. For distances up to 



Interior view of crater, looking N.N.W. 



recently been received, and it must always be 

 regarded as a chief source of our information con- 

 cerning one of the most striking features pre- 

 sented anywhere on the earth's surface. The 

 author, who was one of the firm which obtained 

 possession of the locality, has accumulated by 

 persistent and accurate observation such a wealth 

 of valuable information that his memoir will 

 always remain of the highest scientific value. 



Among the interesting phenomena revealed by 

 the exploration of the western territories of the 

 United States, none yield in importance to the 

 remarkable ringed depression which received the 

 name of "Coon Butte." Situated 70 miles from 

 the famous Grand Canyon of the Colorado, and 

 only 2| miles from the Canyon Diablo, with its 

 innumerable scattered meteorites, the strata under- 

 lying all three localities are the same and are 

 perfectly horizontal. These well-known strata 

 consist of 40 or 50 ft. of purplish-red sandstone, 

 underlain successively by 250 to 300 ft. of lime- 



1 " Meteor Crater (formerly called Coon Mountain or Coon Butte) in 

 Northern Central Arizona." By D. M. Barringer. Paper read beforft the 

 U.S. National Academy of Sciences. 



two miles from the "butte " ejected fragments of 

 the strata are found, those of the limestone being 

 great angular blocks up to thousands of tons in 

 weight, while the sandstone is usually finely 

 divided and often in a completely pulverised con- 

 dition. The minute study of the ejected sand- 

 stones shows evidence of their having been 

 subjected to most intense mechanical forces. In 

 many cases the individual sand-grains are pulver- 

 ised into a fine " silica-meal " ; where, as generally 

 happens, the original bedding planes are visible, 

 they are seen to have been bent and twisted in 

 the most striking manner, and in some cases a 

 lamination cutting across the bedding planes, has 

 been induced strikingly similar to the cleavage of 

 slaty rocks. More rarely fusion of the silica has 

 taken place, and portions of the original sand- 

 grains are involved in chalcedony, a pumice-like 

 material being formed which floats in water. 



Scattered among the other ejected fragments as 

 well as in the "butte" itself are numerous ex- 

 amples of what the author calls "shale-balls," by 

 others, perhaps more appropriately, designated 



NO. 2413, VOL. 96] 



