RAU] NOETH AMERICAN BOULDERS WITH MORTAR-CAVITIES. 57 



A boulder formerly used as a mortar is thus described by Professor 

 Samuel Aughey, of the University of Nebraska: — "Four miles northwest of 

 Nebraska City, on the farm of Hon. J. F. Kinney, is a granitic boulder as 

 large as a small house, on whose top smooth holes have been worn by the 

 Indians in grinding or pounding corn. This boulder is imbedded in a Loess 

 deposit, through which it extends from the Drift below."* Upon inquiry 

 by letter, I learned from Professor Aughey that the most conspicuous of the 

 cavities measures foin-teen inches in diameter and six in depth Its inside, 

 he says, is worn as smooth as glass. The other cavities on this boulder are 

 shallow and faint compared to this one. 



In the Sierra Waco, in the extreme northwestern corner of Texas, about 

 thirty miles east of El Paso, State of Chihuahua, Mexico, the Hon. John 

 R. Bartlett noticed "an overhanging rock extending for some distance, the 

 whole surface of which is covered with rude paintings and sculptures, rep- 

 resenting men, animals, birds, snakes, and fantastic figures. On the 



shelving portion of the place in question are several circular holes in the 

 solid granite, from twelve to fifteen inches deep, which the Indians have 

 made and used as mortars for pounding their corn in ; similar ones being 

 found all over the country where the aborigines have had their habitations." f 

 Afterward, while proceeding in Chihuahua from Correlitos to El Paso, Mr. 

 Bartlett saw a smooth rock covering about half an acre, to the right of the 

 road. In this rock he counted twenty-six cavities within a few feet of each 

 other. They were from twelve to eighteen inches deep and about six in 

 diameter, and had been dug out to serve as mortars.J In a letter addressed 

 to me he adds : — "I remember that there was at that place a great quantity 

 of flint chippings, broken arrow and spear-heads, fragments of pottery, etc., 

 showing that the Indians had spent much time here in making their stone 

 implements." 



I am indebted to Mr. Stephen Bowers, at present residing in Clinton, 

 Wisconsin, for the following account of rocks with mortar-cavities seen by 

 him in California. He says : — 



" These are not unfrequently met with in Santa Barbara County, Cali- 



*Anghey : Sketches of the Physical Geography and Geology of Nebraska ; Omaha, Nebraska, 1880, 

 p. 256. 



t Bartlett: Personal Narrative of Explorations ami Incidents iu Texas, New Mexico, California, 

 Sonora, and Chihuahua, etc. ; New York, 1854, Vol. I, p. 170. 



U6i<i-, Vol. II, p. 370. 



