342 



DR. J. A. SMYTHE ON 



S.S.W. 



JfJf.fc 



COVER 

 20 FEET 



i'/j'" v. Section showing the Hartley Dyke. The dyke is marked A, 

 and is intruded in shales at the lower exposure, and in sandstone at the 

 upper. B represents the cinder-coal, baked by the dyke. The prisms ot 

 this are frequently curved, and they tend to set normally to the whin 

 surfaces. The general direction of the prisms and the two shaly partings 

 are shewn in the sketch. 



