Our success was due in large part to our "unit-food-boxes," a device containing a balanced ration which Professor Harry W. Foote had cooperated with me in assembling. The object of our idea was to facilitate the provisioning of small field parties by packing in a single box everything that two men would need in the way of provisions for a given period. These boxes have given such general satisfaction, not only to the explorers themselves, but to the surgeons who had the responsibility of keeping them in good condition, that a few words in regard to this feature of our equipment may not be unwelcome. The best unit-food-box provides a balanced ration for two men for eight days, breakfast and supper being hearty, cooked meals, and luncheon light and uncooked. It was not intended that the men should depend entirely on the food-boxes, but should vary their diet as much as possible with whatever the country afforded, which in southern Peru frequently means potatoes, corn, eggs, mutton, and bread. Nevertheless each box contained sliced bacon, tinned corned beef, roast beef, chicken, salmon, crushed oats, milk, cheese, coffee, sugar, rice, army bread, salt, sweet chocolates, assorted jams, pickles, and dried fruits and vegetables. By seeing that the jam, dried fruits, soups, and dried vegetables were well assorted, a sufficient variety was procured without destroying the balanced character of the ration. On account of the great difficulty of transportation in the southern Andes we had to eliminate foods that contained a large amount of water, like French peas, baked beans, and canned fruits, however delicious and desirable they might be. In addition to food, we found it desirable to include in each box a cake of laundry soap, two yards of dish toweling, and three empty cotton-cloth bags, to be used for carrying lunches and collecting specimens. The most highly appreciated article of food in our boxes was the rolled oats, a dish which on account of its being already partially cooked was easily prepared at high elevations, where rice cannot be properly boiled. It was difficult to satisfy the members of the Expedition by providing the right amount of sugar. At the beginning of the field season the allowance--one third of a pound per day per man--seemed excessive, and I was criticized for having overloaded the boxes. After a month in the field the allowance proved to be too small and had to be supplemented.