The great freight transporters, therefore, conceived the idea of getting up a scheme for carrying a few letters at a much faster rate from St. Joseph to San Francisco by means of a single horseman riding a pony at full speed. Their idea was that a man should mount a swift pony, well tried for his endurance before starting; that this man should ride fifteen miles straight out into the desert, and that at the end of the fifteen miles there should be a station, a house with a couple of men in it, who would have another pony ready. The horseman was to ride up to this shanty, jump to the ground with his bag of letters, immediately jump on the fresh pony, and rush along another fifteen miles to a similar station. Some of these stations were in settlements, some were in towns, but most of them were on the bleak prairies or in the hills of the Rocky Mountains. The trail was the same as that used by the freight bull trains. The bull-train stations were of course used, but it was necessary to increase the number of stations. Some of the divisions were longer than others. But the average was a distance of forty-five miles; that is, the man who rode one of these divisions of the two thousand miles, rode fifteen miles on one pony, fifteen miles on the second, and fifteen miles on the third. Then he began his return trip of forty-five miles. The longest division was two hundred and fifty miles. Sometimes the country was open and moderately easy for riding. Sometimes it was up rocky gulches or through forests where the riding was hard. It required in the men the hardest kind of physique and endurance, in the ponies surefootedness as well as swiftness. Sometimes in order to keep up the schedule the men were obliged to cover twenty-five miles in an hour on flat country, in order to make up for slower going in the hills. They received about one hundred and twenty-five dollars a month, which was very high pay. But that gave the promoters of the scheme their choice among the best men of the frontier. The letters were carried in mail pouches or bags that hung over the saddle, and no rider was allowed to carry more than twenty pounds. In order to get as much mail within the twenty pounds as possible letters were written on tissue paper. Whatever money was carried was in paper, and one Eastern newspaper printed a special edition on tissue paper for use only on this famous Pony Express. So in the twenty pounds there were hundreds of letters. In fact, the paper was so thin that even a hundred letters would not occupy a space larger than that occupied by an ordinary monthly magazine to-day. The mail pouches were waterproof, and once locked at St. Joseph, Missouri, they were not opened until they were delivered in Sacramento, California, two thousand miles away.