No. 161.] 135 
working this bed, from south to north, the workmen cut through 
the dyke, and finding granite similar to the walls of the bed, sup- 
posed it was terminated at this point, but discovering a small seam 
of ore on the west side they penetrated farther, and again found 
the bed of its original thickness: continuing in the same direction 
as before for 80 feet, it was again crossed by the second dyke, 
and after passing this, the bed resumed its original position. 
Dykes have also been noticed crossing the three other beds in 
the vicinity of the one just mentioned; but as they have been 
little worked, the effects have not been ascertained. The dykes 
crossing these beds were also noticed crossing the first, and, pro- 
bably, when more extensive openings shall be made, each dyke 
will be found crossing all the beds. 
In many cases these dykes cause much inconvenience to the 
workmen, and often produce such confusion in the bed that its 
course cannot be readily traced. 
A vertical dyke was noticed in the Palmer bed, nearly parallel 
to its course: the dip of the bed was about 70^, except where the 
dyke was protruded, and there it was nearly horizontal. 
Two dykes were observed in another ore bed at Clintonville, 
called the Winter ore bed; these dykes embraced between them a 
narrow vein of compact and fine-grained ore, differing from the 
ore in the principal bed, and capable of being manufactured direct- 
ly into steel. Dykes were observed crossing the beds at Duane, 
Malone, and other places; and it is probable, from their existence 
in all the mountain ranges of this region, that they will be found 
in all the beds of magnetic ore, when they shall be sufficiently 
worked. 
The mineral character of these dykes is variable; sometimes 
they are very compact and hard, at others, soft, fissile and wacke- 
like. Where a compact and hard dyke crosses a bed, the ore in the 
immediate vicinity is hard and the bed somewhat narrower. On 
the contrary, where a soft and wacke-like dyke crosses a bed, the 
ore is softer and the bed enlarges. Specimens frequently occur 
where the trap and ore are firmly united. The present is not the 
time to discuss this subject fully, yet suflScient has been said to 
call the attention of the miner to the most important effects produ- 
ced by them. At a future time the subject will be more fully ex- 
plained. 
