LAST SPIKE, COMPLETING FIRST TRANS-CONTINENTAL RAILROAD DRIVEN AT THIS POINT, MAY 10, 1869. The occasion was one of great rejoicing, especially among the citizens of San Francisco. The town went mad with excitement. The festivities commenced two days before the golden spike was driven, and was continued for two days afterwards. Literature contributed its quota to the commemoration of the historic event in the form of a poem from Bret Harte. In crossing the prairie stretches the railway constructional forces were indebted appreciably for their support to the buffalo, which roamed the plains in tens of thousands. The slaughter of this animal was tremendous to provide fresh meat for the camps, and hides for the clothing of the workmen against the blasts and severe cold of winter. Their existence was providential, especially when the Indians succeeded in capturing and destroying the supply trains bringing up provisions. Water often was a serious problem. For stretches of over a hundred miles at a time not a drop could be obtained from the parched land, and specially-built cars had to be pressed into service to transport this indispensable commodity. Some idea of the solitude of the country may be gathered from the fact that during a continuous 600 miles not a single white man or homestead was seen. Before the line was completed a pony express plied between Sacramento and Salt Lake City, and the journey under normal conditions occupied three and a half days. To-day the distance is covered in about one-third of the time. In the course of a few years the traffic on the Overland Route assumed such proportions as to be beyond the capacity of the ill-laid track. The grades were too heavy and the curves too sharp, while rails and bridges were too light. Extensive reconstruction was taken in hand. Banks were abolished, curves were straightened, bridges were rebuilt, the permanent way was re-ballasted, short sections were cut out here, or introduced there, to reduce the mileage--in short, the whole line was rebuilt practically at an expenditure of millions to bring the great highway up to the model of present-day practice. One of the most important of these improvement works was that known as the Lucin Cut-off. This was a daring piece of engineering forced upon the railway by rival lines, which, possessing easier grades and a better-alignment, could haul heavier loads at a speed beyond the capacity of the pioneer road. This adverse factor was experienced very severely around the north end of Salt Lake, where the line plunges into the rugged and broken Promontory Range, to overcome which such heavy grades had to be introduced as to reduce the speed of trains to a crawl of 12 miles per hour.