360 ETHNOLOGY. 



Some estimate of the original maximum height of these tumuli may 

 be formed from the observation that sandy earth, such as that of which 

 they are composed, will not remain iu ipositiou on a slope of more than 

 40° from the horizontal ; they could not, therefore, have been higher, 

 even if raised to a point at the apex, than two-JSfths of the width at the 

 base ; and the very lirst rain or wind would reduce them considerably. 

 As they are now, they would probably remain, with contour unchanged 

 by the action of the elements, for a thousand years to come. 



In one of the largest mounds, ( W,) about twelve feet high, and stand- 

 ing on the highest ground, opened some years since, was discovered an 

 iuclosure of " dry wall," some ten feet square, containing a number of 

 skeletons supposed to have been buried iu a sitting posture, with no in- 

 dication of any covering or floor having ever been there, save the earth 

 of which the whole mound was composed. A portion of this wall, which 

 still remained exposed, we carefully removed for examination, and 

 found it to be built of the fossiliferous limestone common in the neigh- 

 borhood, brought probably from near the river-bank, a quarter of a mile 

 distant and a hundred feet lower ; laid up with tolerable evenness on the 

 inner side. It was about three feet high, two feet thick at the top, and 

 three feet at the base, piled up loosely, the lower stones broad and flat, 

 rather heavier than one man could well carry, and lying on the clean, 

 j-ellowish sand. Some of the stones had been burned red previously to 

 being placed in position. This inclosure was entirely at one side of the 

 center of the mound, and nothing of interest was found in the other 

 part. 



This region has long been occupied by the tribe of Indians known as 

 the Sacs and Foxes, who came from the region of the Saint Lawrence 

 over two hundred years ago, and remained until about the period of the 

 Black Hawk war, about 1832. 



George L, Davenport, esq., of this city, who was born on the island 

 of Eock Island, iu 1817, and was the first white child born in this sec- 

 tion of the country, and who lias been intimately acquainted with the 

 Indians for over fifty years, and speaks their language, informs us that 

 the natives positively had no knowledge of these structures, and paid no 

 attention whatever to them. They had a village or town in the imme- 

 diate neighborhood of the mounds, though their principal town was 

 near the site of the present city of Eock Island. 



It is, therefore, certain that the mounds presented much the same 

 appearance many years ago as now, and that these Indians neither con- 

 structed nor used them. 



No evidences of " intrusive burials" have, in any instance, been dis- 

 covered, and without doubt the mounds have been as at present, and en- 

 tirely undisturbed, for many centuries, until opened by recent explorers. 



We inclose herewith a diagram of the group of mounds, also drawings 

 of the relics exhumed, and a series of photographs of all the well pre- 

 served crania. 



