Mud-slides were another visitation which had to be respected, for time after time a cutting had to be cleared of a viscous mass which had slipped into the excavation. These movements are produced by a kind of sand, which, when it becomes saturated with water, slips and slides in all directions in an amazing manner, carrying everything with it. In winter, when under the grip of frost, the soil looks perfectly safe and stable, but when the weather breaks innumerable springs come to life, and in a short time the whole mass commences to move like a lava stream. In addition to resorting to extreme protective measures against the avalanche where these could not be avoided, some magnificent pieces of bridge-work were carried out at other points to avoid them. In the first instance several were erected in wood to save time, to be replaced by permanent metal structures at a later date. In many cases, however, iron, and in others masonry, had to be adopted in the first instance. There was one gully which perplexed the engineers sorely. It was just a cleft in the perpendicular mountain cliff. The engineers called it the “Jaws of Death,” and the name was appropriate. They had to cross this couloir, and a temporary timber bridge was built by dint of tremendous effort. The engineers congratulated themselves upon their success, but their gratification was short-lived. A constructional train ventured to cross and the structure collapsed under its weight. Here was a dilemma. Work was brought to a standstill and there was grave deliberation. Mr. Van Horne heard of the accident, and hurried to the front. He surveyed the gully, and there and then decided to throw an arched masonry bridge across the breach. It was built, and what was more to the point, it stood; the constructional gangs could get forward. At Stoney Creek there was another trouble of a like nature. The V-shaped ravine was deep and wide, and it was recognised that something different from what had been done in bridge-building up to this point was imperative. Two wooden towers were built on either side to a height of 200 feet, and these supported a single span of 172 feet over the gulch, which was carried out in wood also. From end to end the bridge measured 490 feet, and for years it ranked as the highest wooden bridge on the continent. The timber structure, however, has long since made way for a noble arched steel bridge springing from the rocky sides of the gulch, and it constitutes one of the most graceful bridges on the whole of the system.