616 Transactions of the American Institute. 



Mr. Weir — The sand-blast will not do it. It is resisted by india 

 rubber, paper, or anything soft or elastic. 



Dr. Feuchtwanger — It must be the sharp sand that is used. 



Mr. Weir — It is river sand ; and the sand is used over and over 

 again. A quart of sand will last as long as the machine. 



Mr. Fisher suggested its use in cutting marble or stone, cutting out 

 the interior in useful forms. In tunneling, these forms cut out might 

 pay part of the expense. 



Mr. Weir — They are only experimenting with the process now. I 

 see no reason why they should not be able to tunnel with it, if they 

 can arrange the machine so as to draw off the sand when it has done 

 its work. There is no difficulty about the cutting, for it will cut glass 

 or trap rock quicker than steam will cut ice. 



The President — This seems to be one of the most important inven- 

 tions latety brought before us. It acts upon the principle of giving 

 the sand a high velocity. There is no wasting or sharpening of drills 

 in this process. Another remarkable fact is that the very particles 

 of waste matter taken off in cutting glass, are mixed with the sand 

 and utilized in cutting other glass. 



Mines on the Shores of Lake Superior. 



Mr. J. Disturnell read a paper on the mines of Lake Superior. He 

 mentioned the abundance of veins carrying native copper on the 

 south shore of the lake, from Ontonagon district on the west to 

 Keweenaw Point and Portage Lake on the east. The iron ore 

 deposits near Marquette, which are now very extensively worked, he 

 said had produced 1,000,000 tons of ore this year. The extensive 

 deposits of iron ore, lately discovered on the Menomonee river, and 

 another field in Ashland county, Wisconsin, some twenty miles south 

 of Lake Superior, were also very highly spoken of, the speaker claim- 

 ing that the iron made from these ores surpassed the best Swedish 

 iron in tenacity. 



The last discovery of great importance, that of the silver vein on 

 Silver Islet, near Thunder Cape, was then mentioned. The vein in 

 July last had been sunk upon to a depth of only fifty feet, yet 

 $1,000,000 of treasure had been taken out of it. Other veins on Jerris 

 Island, in Tunder Bay, were also highly spoken of. The whole shore 

 line, from the Pigeon river to St. Ignace Island, was declared to 

 abound in copper, lead, iron and precious stones. 



This land can be purchased from the Canadian government for a 

 dollar an acre in gold. 



