So saying, Snap threw his big Mexican saddle on his pony and started in pursuit, although it was already late in the day.

It soon became evident that his guess had been a correct one. He had lost sight of the beasts for a while, it is true, as they had passed through a thin belt of timber which temporarily hid them from him, but their tracks led straight on for the line. Still, there was lots of time, and, after all, the cattle would not be such fools, he thought, as to climb on to the line itself, where, of course, there could be no feed.

But they did. When Snap next saw them there were about two dozen beasts wandering aimlessly up 'the track' itself, towards the great trestle-bridge which spans the canyon (or gully) of the 'Elk Horn Crik.' The line here runs along a cutting in a hillside, and Snap, leaving his pony below, climbed painfully up to the level of the line.

Once up there, his work was only begun. Do all that he would, he could not get the beasts to leave their perilous pathway. They would not let him get up to them, but steadily jogged on in front of him towards the trestle-bridge. Having tried in vain to get round them, Snap looked at his watch. He had still nearly twenty minutes to spare before the train was due. If he could run the brutes up to the trestle-bridge they would never try to cross that, and he would be able to turn them down the bank, which, terribly steep as it was, was in places just practicable for the sure-footed, prairie-reared cattle.

So he pressed on, driving the cattle against time, as the dark grew ever darker, and the train nearer and nearer to the bridge. At last he thought as he ran that he could hear it far away in the hills, a low, distant, rattling noise, heard plainly for a moment, and then lost again as some high ground was brought by a twist of the line between him and it. The trestle-bridge, however, was in sight, and in another minute he had the satisfaction of seeing the stupid beasts trot up to it, stop, and then, first one, then another, turned and scrambled in headlong fashion down the bank. All except one. One perverse brute, a thorough Texan, 'all horns and tail,' would not follow his companions, but elected to try the bridge.

Perhaps my readers do not know what a trestle-bridge is. To understand the story, it is necessary that they should do so. A trestle-bridge, then, such as the one before Snap, is a bridge of timber, the beams laid at right angles to the line, and each beam about two feet from its neighbour. Across the beams run the iron rails, and between the beams is nothing at all but emptiness. The whole bridge is supported on a huge scaffolding, which rises from the sides of the canyon crossed, and in some cases these bridges are as much as 150 yards from end to end, and 250 feet above the stream which generally races along below. To walk over these bridges by daylight requires a clear head and steady nerves, for, though it is easy enough to stride from beam to beam for a few yards, it becomes more difficult as you proceed: the light gleams off the water below, flickers through the open spaces and dazzles you, while the sight of the vast profound underneath, and the knowledge that one false step will send you whirling between those beams to eternity, has not a steadying effect upon you.

These bridges are, most of them, very narrow, and on the one in question there was but a single line, the shunting station immediately preceding the bridge, which was not considered equal to the weight of two trains at the same time. And on this bridge the black Texan steer had elected to ramble. Clever as a goat, it stepped from beam to beam; then, as the light flickered up into its eyes, it grew nervous and stopped, afraid to come back, and afraid to go on.

Again Snap heard the warning rattle of the coming train amongst the hills, a faint whistle, and then again silence. He had saved all the herd but one. Should he leave that one?

'No, I'm blowed if I will,' muttered the boy, setting his teeth and feeling just as stubborn as the steer in front of him. 'That train won't be up for another quarter of an hour—you can hear it coming for miles on a frosty night like this,' he argued, and boldly enough he started on to the bridge, stepping freely from beam to beam.

The steer, seeing him coming, moved slowly on, trembling in every limb, but still determined not to be headed.