Page:The Boy Travellers in Australasia.djvu/465

Rh long time, when the railway was first proposed, many doubters predicted that it would never be able to pass the Blue Mountains to the plains beyond. The longest tunnel in Australia—five hundred and seventy-two yards—is near Picton, on the Southern line; and the zigzags, bridges, cuts, and fillings are well calculated to excite the admiration of the professional railway man. As for the scenery, it fully justifies the praises which Australians bestow upon it, and the ride over the Blue Mountains is one that everybody who visits the country should take in the daytime.

The engineers of this line claim to have succeeded in solving a problem which has been pronounced impossible by many experienced men, and has been tried elsewhere occasionally, and always with disastrous results—that of having two trains pass each other on a single-track railway. It is done in this way: At the end of each zigzag there is a piece of level track sufficiently long to hold two trains. The engineer of a descending train sees an ascending one on the zigzag below; he runs his train out to the end of a level, and there waits until the ascending one has entered the same level, reversed its course, and gone on its way upward. One of the railway managers said to Doctor Bronson. "There isn't any double track here at all, and yet, you see, two trains can pass