HAMILTON CEMENT ROCK. 405 



Gen. Q. A. Gilmore, U. S. A., tlie highest authority upon this sub- 

 ject in this country, gives as the average tensile strength of the Mil- 

 waukee cement, at the end of seven days, 64^ pounds to the square 

 inch, and that of the standard brands of five of the Rosendale compa- 

 nies at 47 pounds. He also informs me that the commercial product of 

 the Milwaukee stone, used under his direction at Washington city, 

 for making concrete, produced excellent work. Similar testimony is 

 given by others who have used the cement. The excellence of the 

 product may therefore be regarded as established. 



Four large kilns, with a mill and accessory works, have been already, 

 constructed and put in successful operation. The extent of the deposit 

 is abundantly sufficient for all anticipated wants, and its location is 

 convenient and accessible. The description of so interesting and im- 

 portant a resource forms a fitting close for our discussion of the geol- 

 ogy of Eastern Wisconsin. 



