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THE ROYAL SOCIETY OF CANADA 



These clays fall into two groups: those that are high in iron and 

 those that have a low iron content. The iron has an effect on the 

 colour, particularly in the burned state, and also on the refractoriness. 

 The first group, however, are fire-clays, with the exception of No. 5, 

 which begins to soften at cone 20— 1,530°C., and is the least refractory 

 of the group. The others do not begin to soften until the deformation 

 points of cones 26 and 27 — 1,650 to 1,670°C. — are reached. 



Samples 7 to 12 are highly refractory, 10 and 12 being No. 1 fire- 

 clays as they do not deform at cone 33 — 1,790°C. This is the first 

 record of the occurrence of No. 1 fireclays in Canada. 



Owing to their variety of character these clays are suitable for 

 the manufacture of quite a wide range of clay products. Nos. 1, 2 

 and 4 are vitrified at the temperature indicated, but have a very 

 high shrinkage which would require to be corrected by mixing. They 

 are suitable for the manufacture of stoneware goods and sewer pipe 

 or other vitrified products as well as firebrick. Clays 7 to 11 are high 

 grade materials, which would be suitable for retorts, crucibles or fire- 

 brick, in the crude state, and, if washed, for the manufacture of 

 electric and sanitary porcelain as well as floor and wall tiles. 



Only one bed of clay was sampled from the Cretaceous outcrops 

 which occur 6 miles below the foot of Long Portage. This was the 

 massive bed of dark grey, micaceous clay at the bottom of the section ; 

 and, although it looked the least promising in the field from a re- 

 fractory point of view, it turned out to be a No. 3 fireclay that would 

 make a good commercial firebrick. 



