68 PEARL SHELDON 
crops, fairly indicates the lack of development of this set. At 
Enfield Falls this set is fairly good and at Forest Home on Fall 
Creek it is well developed. The same effects may be seen in one 
locality. At Forest Home there are alternate shale and sandy 
layers. The strike joints are better developed in the shales and 
the dip joints in the sandy beds. If the contact between the two 
kinds of rock is sharp both sets often cease at the contact, the strike 
joints passing only through the shale and the dip joints only through 
the sandstone. In other places a change in hardness was found to 
affect the strike joints, sometimes causing them to cease abruptly. 
Often where the strike set is poorly developed in the harder 
Portage beds the set striking a little north of west is unusually well 
developed, almost replacing the genuine strike set. This set 
appears mainly in the harder rocks. It is apparently not of the 
same origin as the strike set, since it is always less uniform even 
where stronger. This is well illustrated in Lick Brook where the 
conspicuous joints are the two dip sets and the westerly set. The 
westerly joints have a large hade and are not uniform but the 
strike joints, though few, are nearly vertical and more regular. 
Hade of the strike joints——In comparing the joint planes and 
folds more can be learned from the hade than from the strike. In 
Fig. 6 the second part of the statement of each average indicates 
the average hade. If the number is heavy it means that the angle 
of hade varied only a few degrees; if light, that the angle varied 
over ten or fifteen or more degrees. A light letter indicates that 
part of the readings were to the north and part to the south. A 
heavy letter means that nearly all were in one direction or the other, 
and the heaviest lettering that none were in the opposite direction. 
The average number is taken from the algebraic sum of the north 
and south readings. 
In the region of the Enfield syncline most of the readings were 
slightly to the south, though only those at Enfield Falls were very 
reliable. At the southern border of the area the few readings taken 
were so variable that they averaged o°. Between the axes of the 
Watkins anticline and Corbett Point syncline the strike joints are 
poor for reading of hade in most places. In many cases the out- 
crops do not permit a reliable reading and in most places the hade 
