He was to deposit his loads and one sledge at the place where he left Bartlett, making a cache on the line of march; then hurry back to Columbia, re-load, and overtake the main party, which would leave the land one day after himself and Bartlett.
By this arrangement, if there were no delays, the main party would begin its third march at the same time when Borup started back; the evening of the third day would find the main party at Borup's cache, and Borup at Cape Columbia; the next morning, when the main party began its fourth march, Borup would be leaving Cape Columbia three marches behind, which difference, with a well-traveled trail to follow, he could probably eliminate in three marches.
It chanced that this sending back of Borup for additional loads to overtake the main party, with the later complications which grew out of it, through the opening of leads between him and the main party, was a link in the chain of delays which might have caused serious trouble, as will be hereafter explained.
In order that the reader may understand this journey over the ice of the polar sea, it is necessary that the theory and practise of both pioneer and supporting parties should be fully understood.

Without this system, as has been amply demonstrated by the experience of previous expeditions, it would be a physical impossibility for any man to reach the North Pole, and return.

The use of relay parties in arctic work is, of course, not new, though the idea was carried further in the last expedition of the Peary Arctic Club than ever before; but the pioneer party is original with my expeditions and for that reason it is perhaps worth while to describe it in detail.
The pioneer party was one unit division, made up of four of the most active and experienced men of the expedition, with sledges lightly loaded with five or six days' provisions, drawn by the best dog teams of the entire pack.

When we started from Cape Columbia, this pioneer party, headed by Bartlett, went out twenty-four hours in advance of the main party.

Later on, when we reached the time of continuous daylight and sunlight through the twenty-four hours, the pioneer party was but twelve hours in advance of the main party.
The duty of this pioneer party was to make a march in every twenty-four hours in spite of every obstacle--excepting, of course, some impassable lead.