"After hard exertion in such garments, if you sit down to rest, or meet a sudden keen wind, as in topping a ridge, you are likely to get a chill--and the next thing is a 'bad cold' or lumbago, rheumatism, or something worse. "Wool, on the contrary is permeable. That is why (if of suitable weight and loose weave) it is both cooler in summer and warmer in winter than cloth made of vegetable fibre. 'One wraps himself in a woolen blanket to keep warm--to keep the heat _in_. He wraps ice in a blanket to keep it from melting--to keep the heat _out_.' In other words, wool is the best material to maintain an equable normal temperature." Camp Site "The essentials of a good camp site are these: 1. Pure water. 2. Wood that burns well. In cold weather there should be either an abundance of sound down wood, or some standing hard wood trees that are not too big for easy felling. 3. An open spot level enough for the tent and camp fire, but elevated above its surroundings so as to have good natural drainage. It must be well above any chance overflow from the sudden rise of a neighboring stream. Observe the previous flood marks.... 7. Exposure to direct sunlight during a part of the day, especially during the early morning hours. 8. In summer, exposure to whatever breezes may blow; in cold weather, protection against the prevailing wind. 9. Privacy. "Water, wood, and good drainage may be all you need for a 'one-night stand,' but the other points, too, should be considered when selecting a site for a fixed camp. "_Water_--Be particularly careful about the purity of your water supply. You come, let us say, to a mountain brook, that issues from thick forest. It ripples over clean rocks, it bubbles with air, it is clear as crystal and cool to your thirsty throat. 'Surely that is good water.' But do you know where it comes from? Every mountain cabin is built close to a spring-branch. Somewhere up that branch there may be a clearing; in that clearing, a house; in that house, a case of dysentery or typhoid fever. I have known several cases of infection from just such a source. It is not true that running water purifies itself. "When one must use well-water let him note the surrounding drainage. If the well is near a stable or out house, or if dish water is thrown near it, let it alone. A well in sandy soil is more or less filtered by nature, but rocky or clayey earth may conduct disease germs a considerable distance under ground. Never drink from the well of an abandoned farm: there is no telling what may have fallen into it. "A spring issuing from the living rock is worthy of confidence. Even if it be but a trickle you can scoop out a basin to receive it that soon will clear itself.