Will's principal difficulty lay in converting his engine to this new use. The driving shaft he found answered admirably as a propeller shaft, the bevel wheels he melted in a crucible to form a propeller. The latter he had to cast himself, making a pattern, moulding it in sand, and pouring the melted brass into the mould.
The petrol was stored in a tank accommodated under the back seat. Will found that some twelve gallons gave him a speed of about forty knots for a four hours' run, which was quite enough for any ordinary expedition.
For a hundred and fifty miles above Ciudad Bolivar, Will soon knew most of the principal tributaries of the Orinoco. In fact the only limit to his expeditions lay in the capacity of his petrol tank, but even this he could supplement on occasion by taking with him a number of extra cans. He had of course one or two exciting experiences; these were inevitable in navigating tropical rivers at a speed of forty knots. More than once the blades of his propeller were injured by half-submerged logs. After tinkering at them some hours on the bank of a creek or river, he would return at four knots to the place from which he had started at forty. These, however, were merely exhilarating incidents; they lent just that spice of risk that made the sport thoroughly enjoyable.
Such risks were due to great speed, but there were occasions when in this very speed lay safety from disaster. One day, having a longer holiday than usual, Will ran down nearly to the mouth of the Orinoco. While going easy at some twenty knots he saw what looked like a bank of water stretching right across the river ahead of him. It did not need a second glance for him to recognize that a tidal wave was sweeping up the river, and threatening to engulf him within a few moments. Before he could bring the hydroplane round, the mass of water, moving at tremendous speed, was almost upon him. He had perhaps five seconds to spare, and drove the hydroplane at its hardest. For a moment it seemed to him that the issue hung in doubt, a very unpleasant moment, as he afterwards confessed. Then the vessel began to draw away, and the immediate danger was over. But for ten or fifteen miles he thought it wise to keep a respectful distance between himself and the tidal wave, which followed him, although at a gradually diminishing speed. Since then he had avoided the Orinoco itself, and limited his excursions to the tributaries within easy distance of the advancing railway.
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We left Will on the bank of the river, the Indian before him, the dead jaguar at his feet. The Indian glanced at his rescuer with a timid, hunted look; then, as if reassured, began to thank him in harsh imperfect Spanish. Will had perceived at once that the man was not one of the workers on the railway.
"Where do you come from?" he asked.
The hunted look returned to the man's eyes. He glanced nervously up and down the river, and towards the opposite bank. Lifting his hand, he described a half-circle with it in the air.
"But where is your home?" Will asked again.
"I have no home, señor," muttered the Indian. "It was burnt with fire."