I slept an hour when I again rose. It was still dark and drizzly, but the glare from the engines working their full power up the ascent was reflected by the hanging clouds, and near objects were dimly visible. I was desirous of seeing what I could of the country, for we were approaching the divide of the water flow of the continent; the one turning to the Pacific, the other to the Atlantic and the Gulf of Mexico. As morning advanced the sky became clear and the features of the country visible. A tunnel two-thirds of a mile long, the Mullan tunnel, is in progress through the summit. At present the rails are connected over the mountain by a surface line, four miles in length, with steep grades. The train was drawn up by two engines and we crept up at a slow pace. On reaching the highest point we came to a stand to admit of an examination of the couplings and of the whole machinery of the locomotive and train. We had now to face the serious work of descent. The heaviest grade is confined to a mile. The inclination, evidently great, was shown by the angle formed by the hanging articles in the Pullman, with the vertical lines of its panels. I extemporized a plummet and line with the silk cord of my glasses, and according to my calculation the gradients we passed over for some distance exceeded two hundred and sixty feet to the mile; in one spot they reached nearly three hundred feet: 5.7 feet to the hundred feet. We left the temporary line and followed the permanent track, the gradient of which I was told is one hundred and sixteen feet to the mile. In our passage over the summit no mountains were visible. The hills through which we passed were but a few hundred feet higher than the track. We crossed the “divide” by a narrow depression, as far as we can judge, of no great depth. The exact length of the completed Mullan tunnel will be 3,850 feet, its height 5,547 feet above sea level. We have reached Helena. We are now in the valley of the Missouri. The second summit, between the Missouri and the Yellowstone Rivers, is about one hundred and forty miles distant from the main summit. Before reaching it I take the opportunity to get some sleep. Seventy miles from Helena we come to Gallatin. At this spot the Missouri may be said to commence. It is fed by three important tributaries, the Jefferson, the Madison and the Gallatin, all rising within the periphery of a semi-circle of mountains visible to the south and east of us.