"But the Red Sea is not of very much interest to Britain, is it?" said Bob, questioningly.
"Maybe no, though I canna allow that any part o' His Majesty's ocean is without its due importance; but, ye see, Aden protects India by watching the ships that come through the Red Sea, and forby there's no vessel o' war belonging to another nation could steam past withoot comin' in for coal——" This in a burst of patriotic fervour. "Why, when the German Emperor's brother went oot to China, a year or so back, in his big gunboat, he touched at nothing but British ports all the way." Mackay chuckled with amusement at the recollection. "There used to be a tree growing at Aden," he said again, when they recovered themselves, "but some one that doesn't believe in oddities has evidently cut it down."
Nothing but sand and bare rocks could be seen all around, so his surmise was probably quite accurate.
"Aren't there some huge tanks near here?" asked Bob. "I heard that they were the only sight worth seeing in Aden."
"You're quite richt; they're no exactly in Aden, being about five miles back in the hills. But we have just time to visit them."
He called a waiting garry at once, and directing the Somali driver, they set out to view the giant reservoirs which date their origin away back in the mists of antiquity. Bob and Jack looked very different individuals from what they were a few weeks before. Dressed in whites, and wearing sun-helmets, they seemed already to be quite accustomed to the heat; the old tired look had vanished from their faces, and the light of awakening interest was in their eyes. As for Mackay, under his big, umbrella-shaped head-covering, the same kindly face was visible, perhaps a little redder than it was before, but, as he said himself, it was regaining its natural tan.
"I believe in harmony o' colour," he gravely said, "and there should be nae contrast between my moustache and its surrounding beauties."
When they reached the tanks, which in appearance were as huge caverns graven out of the solid rock, the engineering training of the boys was at once evident by their remarks.
"What a mighty work it must have been," mused Bob.
"King Solomon's Tanks," announced Mackay, taking upon himself the onus of dispensing knowledge, "were built, or rather excavated, about three thousand years ago. You will observe that they are so situated as to catch the natural drainage o' the surrounding country, and when rain fell, which was seldom, the tanks got filled, and—and when it didna fall—of course, they remained empty!"