The Rock itself is a compact limestone, a form of grey dense marble varied by beds of red sandstone. It abounds in caves and fissures, and advantage has been taken of these facts to bore galleries, the most celebrated of which are St. Michael’s and Martin’s, the former 1,100 feet above the sea. Tradition makes it a barren rock; but the botanists tell us differently. There are 456 species of indigenous flowering plants, besides many which have been introduced. The advantages of its natural position have been everywhere utilised. It bristles with batteries, many of which can hardly be seen. Captain Sayer tells us that every spot where a gun could be brought to bear on an enemy has one. “Wandering,” says he, “through the geranium-edged paths on the hill-side, or clambering up the rugged cliffs to the eastward, one stumbles unexpectedly upon a gun of the heaviest metal lodged in a secluded nook, with its ammunition, round shot, canister, and case piled around it, ready at any instant.... The shrubs and flowers that grow on the cultivated places, and are preserved from injury with so much solicitude, are often but the masks of guns, which lie crouched beneath the leaves ready for the port-fire.” Everywhere, all stands ready for defence. War and peace are strangely mingled. Gibraltar has one of the finest colonial libraries in the world, founded by the celebrated Colonel Drinkwater, whose account of the great siege is still the standard authority. The town possesses some advantages; but as 15,000 souls out of a population of about double that number are crowded into one square mile, it is not altogether a healthy place—albeit much improved of late years. Rents are exorbitant; but ordinary living and bad liquors are cheap. It is by no means the best place in the world for “Jack ashore,” for, as Shakespeare tells us, “sailors” are “but men,” and there be “land rats and water rats,” who live on their weaknesses. The town has a very mongrel population, of all shades of colour and character. Alas! the monkeys, who were the first inhabitants of the Rock—tailless Barbary apes—are now becoming scarce. Many a poor Jocko has fallen from the enemy’s shot, killed in battles which he, at least, never provoked. The scenery of the Straits, which we are now about to enter, is fresh and pleasant, and as we commenced with an extract from one well-known poet, we may be allowed to finish with that of another, which, if more hackneyed, is still expressive and beautiful. Byron’s well-known lines will recur to many of our readers:— “Through Calpe’s Straits survey the steepy shore; Europe and Afric on each other gaze! Lands of the dark-eyed maid and dusky Moor Alike beheld beneath pale Hecate’s blaze; How softly on the Spanish shore she plays, Disclosing rock, and slope, and forest brown, Distinct though darkening with her waning phase.”