74 Lieut. Baddeley on the Geology 
the boat hook was removed to the place where he stood, and 
the same thing repeated. By ascending in this manner, it 
took eighteen stations to reach the top of the slope, which 
multiplied by the height of the boat hook, minus the height 
of the eye (in thls case 5 fect 6 inches,) gives a product of 180 
feet, which added to 75 feef, the sum of the height of coe 
Jumnar and amorphous basalt, previously measured by drope 
ping a line from the summit, makes a total height above the 
sea of 255 feet. 
In some places the upper part having fallen away, the 
columns under are left without any other burthen to support 
than thatof their own weight ; in these cases it is often pos- 
sible to push them over with the foot, by climbling up and 
going behind them. ‘The summit is flat and covered with 
moss and turf; its shape is oblong, and it is widest in the 
middle, Thecolumns pass all round, andthere is only one 
way of reaching the summit. 
This formation extends to another island to the westward, 
called Saddle Island, from which, Castle Reef Rock is di- 
vided by an arm of the sea, called bythe fishermen Castle 
Reef Tickle. The width of this arm is not more than 120 
yards, and its depth is sufficient for the largest vessels, 
There is no essential difference inthe basaltiform appeare 
ance of Saddle Island ; the occurrence, however, of three 
caves, on the side towards the sea, affords, upon an exami- 
tion of them, strong presumptive evidence that these columng 
traverse the mountain, and with the same regularity and 
close juxta position they exhibit on the outside. Thc deep. 
estof these caverns was foundto be 20 yards deep by 15 
yards wide in the middle—the floors were strewn with the 
fragments of columns, and the sides were ornamented by those 
which their removal exposed to view—the ceiling was as 
smooth as thatofa room but of almost an iron blackness. 
The thickness of amorphous basalt above was from 30 to 40 
feet, 
The 
