NEW MINING FIELDDevelopment North Of Great Slave Lake Is PredictedEDMONTON.—Mines Minister T. A. Crerar said in an interview on arrival here that an important new mining field Is in the making north of Great Slave Lake In the Yellowknife country. He predicted an Immense development in the north country and the whole valley of the Mackenzie In the next 25 years.Accompanied by Dr. Charles Cam-sell, deputy minister, Mr. Crerar conferred with Maj.-Gen. iV. W. Poster, special Canadian commissioner for northwest defence projects, and will visit Elk island and Jasper National parks and the McMurray oil sands. He intends alao to pay a courtesy call on Premier E. C. Manning and Lieu-1 tenant-Covernor J. C. Bowen.