On the way the force overtook a party of pioneers, sent out by Tom in advance, armed with spades, mattocks, knives, and similar implements for cutting away the brushwood, erecting stockades, and performing the other operations necessary in the forest. At every third mile Tom ordered his men to erect a rough redoubt or block-house of earth and wood, by means of which communication might be maintained with the village if it should be invested. At each of these he left a small garrison with arms and provisions. The last redoubt before entering the forest was of larger size than the rest, and in it he left a larger garrison and a more plentiful store of food and ammunition. There was, he judged, ample time for this work of construction, for the African native is extremely quick; and, besides, the Arabs could scarcely reach the outskirts of the forest within four days at their best speed, and that period might be almost indefinitely extended if the warriors already despatched to harass them carried out their instructions thoroughly. Tom saw that, having to deal with an army no doubt immensely superior in point of numbers as well as of armament to his own, he could only impede their march; he could not hope to stop it. A general engagement could hardly be risked. It might easily result in the total destruction of his force and the subsequent storming of the village. It was his object, therefore, to fight a series of small engagements while the enemy were still in the forest, and he hoped, by carefully choosing the moment, to win such success as should give his men new confidence in themselves, each other, and him.
Entering the forest at length, he was soon met by messengers sent back by the leaders of his skirmishers, with the information that the Arabs were advancing in great force behind a screen of native levies, who were thoroughly skilled in forest-fighting. All that the chiefs had been able to do was to maintain a running fight, laying simple ambushes, darting in spears and arrows whenever they saw an opportunity, and retiring as soon as the head of the main force appeared.
From the description given by the native couriers, who reached him almost every hour from the front, Tom, making due allowance for exaggeration, concluded that the hostile force numbered in all some five thousand men, with an almost equal number of carriers. They were marching in a column nearly five miles in length, the narrowness of the forest track rendering it almost impossible to proceed except in single file.
On the second day, Tom, marching now at the head of his troops, came to a broad stream, which, as he had learnt already from his scouts, was in full flood from the recent rains. He was hardly prepared to find it so broad and deep as it was, and though it could easily be swum, it was necessary to find a ford if the food and ammunition were to be got across in safety. The bank was steep, and covered with rank bush growing as high as a man. "Better try myself; it will be quickest in the long run," he said to himself, and, sliding down the slippery bank, he waded into the water. It was icy cold, and as he walked towards the middle of the stream, and the water rose as high as his chest, he gasped for breath. The current was fairly strong; he could scarcely keep his feet; and at last he found it impossible to do so. But only a few yards to the right he noticed that the water was swirling and foaming, and, swimming to that point, his feet, as he expected, touched bottom on some rocks. There he waded across, clambered up the bank, and ordered his men on the other side to cut a new path down the shelving bank opposite the ford he had so opportunely discovered. There the whole force crossed, the water reaching a little above their knees, and Tom, having seen the passage safely completed, and now shivering with cold, was glad to swallow a dose of the quinine included with a few indispensables in Mbutu's bundle.
Tom had a certain advantage in the mobility of his force. Never more than a day's march from a food-supply, he was able to dispense with the greater part of his carriers; for his troops were able to take with them sufficient for their immediate needs. Retaining only one thousand carriers to bring up supplies from the large redoubt, he employed the rest in assisting the troops to fell trees and build abattis at various defensible points along the route.
He found, however, that after deducting the troops left behind in the village, and the garrisons of the redoubts, he had scarcely more than two thousand five hundred men to meet the Arab advance. The question was, how to dispose of this force to the best advantage. Learning from the couriers at the end of the third day's march that he had come within ten miles of the head of the Arab army, he halted at a particularly dense part of the forest, and proceeded, at a distance of some fifty yards from the track, to cut a path a mile and a half long parallel to it. Darkness was falling, the Arabs would certainly halt for the night, and by employing all his men he hoped to complete the clearing of the new road by the morning. At the same time he built a stockade of trees masked with shrubs at the southern end of the main track. His plan was to arrest the enemy by the stockade, which was so artfully located at a slight bend in the path that it could not be seen until they were within a yard of it, and then to attack them in flank from the bush. By cutting the parallel road he had made it possible for his men to move up and down at will over a length of a mile and a half, and to choose the best positions for pouring in their fire upon the surprised and congested enemy. The task was completed long before dawn, and there was time for the whole force to snatch a little much-needed sleep before the hard work that might be expected on the following day.
A year before, Tom would have found it difficult, almost impossible, to realize what forest fighting meant. Here he was in an immense forest, stocked with trees from one hundred to two hundred feet high, their dense foliage interlocked overhead, the gaps between them filled with an undergrowth of matted bush, rubber shrubs, creepers, and dwarf-palms, so thick that the eye could never penetrate more than twenty yards at the farthest. The path was a mere foot-track, along which it was only possible to march in single file. At some points, where the soil was soft, the path had in the course of generations been worn down to a lower level, and seemed like a railway cutting between high banks of dead leaves and debris. At other points it wound round a fallen tree, no one having taken the trouble to remove the obstruction. Here and there, too, great festoons of monkey-ropes, mingled with orchid blossoms, hung from tree to tree across the track, so thick that progress was impossible until they had been lopped down with knives and axes.
Tom, as he lay on the bank to rest, felt the oppression of the confined space even more than he had felt it during his previous wandering through the forest. The recent rains had caused a rank smell to rise from the decaying vegetable matter all around him, and he would not allow himself to think of the ever-present dangers of malaria. The night was cold. Not wishing the enemy to discover his position or the positions of his men, he had given orders that no fires were to be lighted, and, but for the cloth which Mbutu had brought by his instructions, he would have shivered all night long, and in all probability been prostrated with racking pains in the limbs. As it was, he rose from his brief sleep cold and hungry, but feeling ready for anything, and indeed anxious to meet the long-looked-for enemy at last. After a breakfast of bananas and potato-bread, he sent messengers forward to instruct the skirmishers and scouts to fall back. He thought that if the harassing attacks ceased for a whole day, the Arabs might conclude that their enemy had become disheartened, and might thereby be tempted to relax their vigilance.
At the farther end of the newly-made parallel track there was a large tree, which, dominating the intervening space and overlooking the main path, provided a convenient refuge from which it was possible to obtain a good idea of the strength and composition of the enemy's force as it came in sight. Tom found that he could easily climb the tree to such a height that, while secure from observation himself, he could act as his own intelligence officer and not have to trust to the magnifying eyes of his men. If the Arabs were ten miles away the day before, he concluded that it would probably take them the whole day to reach this point, the forest being dense, and the path obstructed in many places by the encroaching bush. He knew that his men would not be very willing to fight during the night, and there seemed every likelihood that the action would not begin until the next day. It turned out according to his expectation. The Arabs, after the harassing movements of their enemy on the previous days, had evidently resolved to take advantage of the lull to enjoy a thorough rest, for the whole day went by without a sign of them. Tom again camped with his men for the night, placing sentries for several hundred yards along the path to prevent anything in the nature of a surprise.
He was up with the dawn again, and sent forward a few scouts to reconnoitre. These returned by and by, and reported that the enemy had marched forward only three miles the previous day, and were now about seven miles away. Being anxious that they should be surprised as completely as possible, Tom refrained from sending forward many scouts, lest some incautious action should give the Arabs warning. In the afternoon, judging that the force must be drawing near, he placed some seventeen hundred men along the parallel road, and eight hundred behind the stockade, ordering the musketeers among the latter not to fire until they were actually attacked, or until they heard firing in their front.