24 
CRUISE OF H.M.S . CHALLENGER. 
water on that collected from rain in tanks. Artesian 
wells, however, have been sunk on the Neutral 
Grround, and now yield an extensive supply ol 
excellent, pure water. 
On the east side of the Rock, near Catalan Bay, 
there is a sand formation similar to that on the Neu- 
tral Ground ; this deposit has attained the enormous 
height of 1000 feet. There is no road round this 
side, for a portion of the sand has been excavated 
at the point where the isthmus joins the Rock, and 
the water of the bay flows in so as to leave only a 
narrow low dyke of firm ground. 
The adjacent Spanish settlements of Campamiento 
and San Roque are much resorted to by excursionists 
from Gibraltar, and during the summer months are 
selected by numerous families for a prolonged stay. 
However little pleasure or interest a ride over this 
arid and sandy plain affords, when# once arrived at 
Campo, the rider enjoys a most charming prospect, 
as there is probably no other point from which the 
isolated Rock appears more grand or picturesque 
than from this neat little village. 
