108 DATEJfPORT ACADEMY OF XATUKAL SCIEXCES. 



did not leave the spot until the tablets were unearthed by the hands of the 

 former. This forever silences the doubt in regard to the intrusion or 

 interi^olation of these tablets, for, taken in connection with the frozen 

 state of the ground, it makes such an act simply impossible. 



DESCRIPTION OF THE TABLETS. 



The material of the tablets is the bituminous shale, which is abund- 

 antly found in the coal regions, and crops out in various places in this 

 vicinity, notably on Rock River. This shale is quite light and very soft, 

 and has the following composition, the analysis being due the kindness of 

 our associate, Mr. J. H. Harrison : 



Water (moisture) 74 parts. 



Inflammable matter (carbon, bitumen, etc.) 316 parts. 



Ashes 610 parts. 



1000 



Though this material is found so abundantly in this vicinity, it is not 

 a fair inference to conclude that the tablets were necessarily made here, 

 for the substance of which they are composed is equally abundant in 

 very many other places, indeed, wherever coal is found. The large 

 tablet, as found, had a thickness of one and a half (1*) inches, and is of 

 an iiTegular, quadrilateral shape, twelve (12) inches long on the unbroken 

 edge, and from eight (8) to ten (10) inches wide. Judging from the sac- 

 rificial or cremation scene, nearly or quite one-half of this engraved tab- 

 let is missing. 



As found, the stone was split into two parts by a separation in the 

 plane of cleavage, and the upper half (the cremation scene) was unfortu- 

 nately broken also into two pieces by the blow of the spade, which re- 

 vealed its existence in the soft earth where it rested. 



The smaller tablet or calendar stone is composed of the same material, 

 and is in shape an imperfect square, with nearly straight sides of seven 

 (7) inches in length ; the thickness, which is not vmiform, averages five 

 eighths (f ) of an inch ; the holes bored near the upper corners, apparently 

 for the purpose of suspension, have each the diameter of three-eighths 

 (f) of an inch. 



An examination of the surfaces of the stones with a magnifying glass, 

 showing the marks of the original polishing, or smoothing would seem to 

 indicate that they had not weathered much. Whatever signs of weath- 

 ering exist are equally visible everywhere, that is to say, they have weath- 

 ered alike the surface and the cuts. The exceedingly friable nature of 

 the stone would indeed render much exposure to weathering influences 

 impossible. The incisions, which are no where very deep, have a depth 

 which is uniformly as the width, and seem to have been made with a 

 cutting point or edge held at angle of 45 degrees to the surface. 



CALENDAR STONE (PLATE III). 



In addition to the representation on the plate, a very short notice of 

 the marking on this;3tone will suflSce. The central circle was described 



