354 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



is effected when it passes over the shoals above Detroit, where there is a 

 maximum depth of only fifteen feet, with great width. 



Finally, in the Penny Magazine of August 6th, 1842, there is an article 

 on ground-ice or ground gru, the latter being the term used in Lincoln- 

 shire, where in the river Don it was observed by the author. Dr. Far- 

 quharson. He says, " Gru is the name by which the people of Lincoln- 

 shire designate snow saturated with or swimming in water ; and as the 

 ice formed at the bottom of rivers very nearly resembles that in appear- 

 ance, a better name than ground gru could hardly be given." Again, he 

 says, " when it begins to form at the bottom, it aggregates in forms, 

 somewhat resembling the hearts of caulitlovver." 



The synonyms for this form of ice, as far as I make out, are the fol- 

 lowing, viz: Grundeis (German); Frazeau (Canadian French); Lolly 

 (seal-fishermen) (lolly, soft, as in lob-lolly — gruel or mush, and lollepop — 

 soft candy) ; ground-ice; anchor-ice; and ground-gru, (Lincolnshire.) 



Whether the ground-ice continues to form on the rapids after the final 

 freezing of the surface for the winter takes place, is not yet definitely 

 known ; but as an observer (Dr. Jackson, .Journal of the Royal Geo- 

 graphical Society, Vol. 5), states that such is the case in regard to the 

 river Neva, in Russia, when covered with three feet of ice and as much 

 snow, it is probable that here it also continues to form. This would ac- 

 count for the growth of the ice opposite the city, after it forms, the ac- 

 cretion below being sufficient not only to counteract the effect of the 

 enormous loss by evaporation from the upper surface ; but to so exceed 

 it as to produce a total thickness of three feet. 



Exploration of Six Indian Burial Grounds in the Vicinity of the 

 Mouth of Rock River. 



BY REV. J. GASS. 



On the 29th of November, in company with Mr. Toellner of Moline, I 

 visited five Indian burying places on Rock River, and one on the Mis- 

 sissippi. We found on the right bank between the mouth of the river 

 and the first railroad bridge, three of these groups of Indian graves. 

 Some of the graves were situated so close to the running stream that a 

 number of them were swept away by the torrents of high water. 



The graves are all in rows similar to those of the Sioux at Camp 

 McClellan. In the one nearest the bridge they are arranged in the form 

 of a hollow square. We opened some of the graves. They were about 

 five feet deep, and in each of them only one body had been buried, and 

 no accompanying relics of any kind were discovered. 



The foui'th cemetery we explored is on the island near Milan. In dig- 

 ging a ditch for the use of a factory, built there some years since, a num- 

 ber of graves were disturbed, and many relics of glass and bronze were 

 found similar in form and material to those usually found in modern 

 Indian graves. 



The fifth burying place we visited is situated about a mile above 

 • Milan, on the left of the river. Close by it is a Siind-pit, and in digging 



