Ha eed 
THE ISLANDS. 205 
ANALYSES OF HyprAautic LAYERS or WATERLIME FROM SoutH Point, Put-1n-Bay, 
BY Dr. H. ENDEMANN. 
1 2 3 5 
CarhonaterOlslinm eit, scoressee scesceces 51.43 49,11 51.28 42.95 
Carbonate of magnesia............0... 40.24 36.87 39.65 39.79 
Sill COMUNE AN Aran Seeaee ccciuccess sbedeces 3.85 10.05 7.80 13.30 
As is usually the case in the State of New York, the Waterlime group 
on Put-in- Bay Island contains certain layers which make good hydraulic 
cement. These are the flaggy layers which form No. 4 of the section 
given on a preceding page. No satisfactory test has ever been made of 
the quality of this stone, but some of the layers are known to possess 
hydraulic properties. It is probable that, with some care in the selec- 
tion of the material, good cement could be produced in any desired 
quantity, and at little expense, at South Point. 
In my examination of the geology of the islands I have been greatly 
aided by the cordial and efficient co-operation of my friend Capt. John 
Brown, of Put-in-Bay, and I take this occasion to return to him my sincere 
thanks for numberless favors of various kinds. I also desire to acknowl- 
edge my obligations to Mr. Norman Kelly and Mr. John W. Dunn, of 
Kelly’s Island; to the first, for numerous fine specimens taken from his 
extensive quarries; to the second, for the intelligent appreciation and 
preservation of the magnificent glacial furrows uncovered at the quarries 
of G. W. Calkins & Co., and also for a series of photographs illustrating 
them. 
