144 
Mr. Weaver on the 
Powerscourt Park and waterfall. Above the waterfall, the mica slate 
preserves the same character as on the summit of Djouce, but it 
ranges here 20° north of east, and dips 55° toward the south-east ; 
and in the waterfall itself, the rock, over the inclined face of which 
the water rushes in a fall of about one hundred and twenty feet, 
exhibits the same dip. 
§ 25. Following the Glenisloreane stream, from the waterfall 
downward to its junction with that of Glencree, the rock, wherever 
it juts out on the right and left banks, presents only mica slate; but 
it is soon concealed, as the banks become occupied high up by 
alluvial matter, partly of a calcareous nature ; and these banks are 
beautifully clothed with wood, plantations, and the rich verdure of 
a cultivated soil. The mica slate, however, is probably immediately 
succeeded by quartz rock in the right bank, as this substance is the 
principal constituent of Coolakay and Long Hills, which bound the 
glen on this side. 
§ 26. The mica slate in its progress to the south, keeps clear of 
Lough Tay, crosses Lough Dan, and traversing the higher part of 
Carriggeenduff, enters Glenmacanass a little below the waterfall, 
which flows down a face of granite about two hundred feet in 
height. From hence downward, mica slate occupies the entire 
eastern bank of the stream, constituting the mass of Carriggeenduff 
and Scar Hill ; but the western bank is differently circumstanced, 
being lined for about one thousand yards in width by mica slate, and 
thence downward by granite only, until within half a mile of 
Laragh barracks, when mica slate re-appears for the remainder of 
the distance. Hence it appears that the agent which produced the 
glen, first broke through granite and mica slate, then followed the 
line of junction between these two rocks, and lastly broke again 
