114 FRAGMENTS OF SCIENCE. 
full of good nature, and engaged us on the spot to dine 
with him that day. 
We sought the town-major for a pass to visit the lines. 
While awaiting his arrival I purchased a stock of white 
glass bottles, with a view to experiments on the color of 
the sea. Mr. Huggins and myself, who wished to see the 
rock, were taken by Captain Salmond to the library, where 
a model of Gibraltar is kept, and where we had a useful 
preliminary lesson. At the library we met Colonel Maberly, 
a courteous and kindly man, who gave us good advice re- 
garding our excursion. He sent an orderly with us to the 
entrance of the lines. The orderly handed us over to an 
intelligent Irishman, who was directed to show us every- 
thing that we desired to see, and to hide nothing from us. 
We took the " upper line," traversed the galleries hewn 
through the limestone; looked through the embrasures, 
which opened like doors in the precipice, toward the hills 
of Spain; reached St. George's hall, and went still higher, 
emerging on the summit of one of the noblest cliffs I have 
ever seen. 
Beyond were the Spanish lines, marked by a line of 
white sentry-boxes; nearer were the English lines, less con- 
spicuously indicated; and between -both was the neutral 
ground. Behind the Spanish lines rose the conical hill 
called the Queen of Spain's Chair. The general aspect of 
the mainland from the rock is bold and rugged. Dou- 
bling back from the galleries, we struck upward toward 
the crest, reached the signal station, where we indulged 
in " shandy-gaff " and bread and cheese. Thence to 
O'Hara's Tower, the highest point of the rock. It was 
built by a former governor, who, forgetful of the laws of 
terrestrial curvature, thought he might look from the tower 
into the port of Cadiz. The tower is riven, and it may be 
climbed along the edges of the crack. We got to the top 
of it; thence descended the curious Mediterranean Stair a 
zigzag, mostly of steps down a steeply falling slope, amid 
palmetto brush, aloes, and prickly pear. 
Passing over the Windmill Hill, we were joined at the 
" Governor's Cottage " by a car, and drove afterward to the 
lighthouse at Europa Point. The tower was built, I be- 
lieve, by Queen Adelaide, and it contains a fine dioptric ap- 
paratus of the first order, constructed by Messrs. Chance, of 
Birmingham. At the appointed hour we were at the Con- 
