While the scouts were gone he ordered the men to form an entrenched camp. For all he knew the enemy might be lurking in the forest ready to take advantage of any slip, any sign of unwariness; and until he had located the Arabs, and, if possible, discovered what their strength was, it was impossible to form definite plans for an attack on the fortress.
Towards dusk Mboda returned with his men and reported that the path grew wider and less obstructed as it bent northward. They had seen one canoe, manned by a crew of half a dozen Manyema, who had shipped their paddles and jeered when they caught sight of the scouts. The best marksmen among these had tried a shot at the canoe, which, though it had fallen short, had been sufficient to set the men hastily paddling towards the island. Mboda had tried to see exactly where their landing-place was, but the shore of the island appeared to be an impenetrable wall of jungle.
When the evening meal had been eaten, and the camp-fires were lit, Tom sent for his prisoners again and subjected them to a further interrogation. He learnt that the lake was fed by a small river flowing from the north-east, as well as by numerous rivulets at other points. The surplus water escaped on the left, where it formed a fairly large stream. The mouth of the river on the north-east was fringed with dense clumps of reeds.
"Since there are apparently no canoes to be captured we shall have to make some," said Tom to himself; "and that will take time. I hope our stock of food will last till we capture the Arabs' stores. Dug-outs will be the easiest to make, I suppose. These men of mine have never made a canoe in their lives, I suspect. Msala," he said aloud to the katikiro, "could you make a canoe, do you think?"
Msala looked doubtful, but at length said that he thought he could if Kuboko would show him the way!
"Like the genius who had never played the fiddle, but thought he could if he tried!" thought Tom. "O wise man!" he said. "That's a good answer. I'll try to show you the way, though I've done nothing of the sort since I broke a dozen pen-knives carving a sailing-boat when I was a boy of twelve. The first question is, where are these canoes to be made, eh?"
Msala could give no assistance towards solving this problem, but Tom soon thought it out for himself. The outlet on the west was wide, the prisoner had said, and comparatively free from reeds. Operations there would run the risk of being disturbed, for no doubt the enemy possessed a considerable flotilla on the island. But the reeds at the mouth of the river on the north-east would serve as a screen, and a few sharpshooters carefully posted would easily defend the position against attack.
"That's the place, evidently," said Tom. "To-morrow morning, Msala, we'll start building our fleet. Now for sleep, my men--we must be up early in the morning."
Next day he ordered his men to build a block-house where he had emerged from the forest, so as to intercept any fugitive Arabs who might have found their way back to the lake, and to keep a general look-out. Leaving a garrison of two hundred men there, he started with the rest towards the north-east corner, which they reached after an arduous march of fifteen miles, the path having to be cut after they left the principal landing-stage opposite the eastern shore of the island. It happened to be a particularly bright and clear day, and at different points along the route Tom caught glimpses of the island, which enabled him to form a fairly good idea of its character and extent. He judged it to be about a mile long; it was covered with vegetation of the nature of jungle, tall forest-trees being conspicuously absent. The prisoners pointed out the exact spot, near the centre of the island, where the fort was situated, but so dense was the thicket that not a corner of it was visible. They explained that, while the forest-growth at the shore was allowed to remain in its pristine wildness, within this fringe and behind some plantations the ground had been cleared, and the fort, capable of containing two thousand men, had been built on a slight eminence in the very centre of the island. It consisted of a double row of palisades, fifteen feet in height, the exterior palisade being defended throughout its whole circuit by a glacis, with a slope of one foot in four.
"So there are two difficulties to surmount," thought Tom. "First, the difficulty of reaching the island and landing my men; then the difficulty of storming a fort defended by such high outworks and a glacis to boot. It's a case of scaling-ladders as well as canoes. A great piece of luck that I thought of bringing so many artificers among the carriers."