In the "Nansen Cooker," which we used, a maximum result is secured from the heat of the primus. The hot gases from the combustion of the kerosene, before they escape into the outside air, have to circulate along a tortuous path, passing from the hot interior to the colder exterior compartments, losing heat all the time. Thus a hot hoosh is preparing in the central vessel side by side with the melting of snow for cocoa or tea in the annulus. By the combination of "Nansen Cooker" and primus stove one gallon of kerosene oil properly husbanded is made to last for twelve days in the preparation of the ordinary ration for three men.
[TEXT ILLUSTRATION] [ [!-- H2 anchor --] ]
Section through a Nansen Sledging Cooker mounted on the primus
The subject of food is one which requires peculiar consideration and study. It is assumed that a polar expedition must carry all its food-stuffs in that variety and quantity which may approximately satisfy normal demands. Fortunately, the advance of science has been such that necessaries like vegetables, fruit, meats and milk are now preserved so that the chances of bacterial contamination are reduced to a minimum. A cold climate is an additional security towards the same end.
Speaking generally, while living for months in an Antarctic hut, it is a splendid thing to have more than the mere necessaries of life. Since one is cut off from the ordinary amenities of social existence, it is particularly necessary that equipment and food should be of the very best; in some measure to replace a lack which sooner or later makes itself keenly felt. Explorers, after all, are only mortal.
Luxuries, then, are good in moderation, and mainly for their psychological effect. After a spell of routine, a celebration is the natural sequel, and if there are delicacies which in civilization are more palatable than usual, why not take them to where they will receive a still fuller and heartier appreciation? There is a corresponding rise in the "tide of life" and the ennui of the same task, in the same place, in the same wind, is not so noticeable. So we did not forget our asparagus and jugged hare.
In the matter of sledging foods, one comes down to a solid basis of dietetics. But even dietetics as a science has to stand aside when actual experience speaks. Dietetics deals with proteins, carbohydrates, fats, and calories: all terms which need definition and comprehension before the value of a sledging ration can be fundamentally understood. When the subject was first introduced into table conversation at the Hut, it was regarded somewhat suspiciously as "shop." But it gradually won interest simply because it was of such vital concern.
In sledging there is undoubtedly a critical allowance which will yield the best results. Circumstances alter cases, and the correct ration under one set of conditions cannot be expected to coincide with that in another situation. Thus, the journey may be conducted under conditions of great cold or of comparative warmth, by man-hauling or auxiliary power, at sea-level or on an altitude, through regions where there is a reasonable hope of securing additions of meat by the way, or across barren tracts devoid of game. In each instance particular demands must be supplied.
In selecting the articles of diet, idiosyncrasies of individuals should be consulted in reason, and under no consideration should anything be taken which bears the slightest stigma of contamination. It remains, then, to discriminate those foods which contribute the greatest amount of nutriment for a given weight, and which, inter se, preserve a proper dietetic balance. Variety is very desirable, provided that there is no important sacrifice in nutrient value. The proof of a wisely selected ration is to find at the end of a long sledge journey that the sole craving is for an increase in the ration. Of course, such would be the ideal result of a perfect ration, which does not exist.
Considering that an ordinary individual in civilization may only satisfy the choice demands of his appetite by selecting from the multifarious bill of fare of a modern restaurant, it will be evident that the same person, though already on the restricted diet of an explorer, cannot be suddenly subjected to a sledging ration for any considerable period without a certain exercise of discipline.