One person works the “drill-stick” with a rude bow, and with his other hand holds a piece of stone or of wood above it, both to steady it and to give the requisite pressure—­gentle at first, and increasing judiciously up to the critical moment when the fire is on the point of bursting out.  Another man puts his hands on the lower piece of wood, the “fire-block,” to steady it, and holds a piece of tinder ready to light it as soon as fire is produced.  If a serious emergency should occur, it is by no means hopeless to obtain fire after this method.  A large party have considerable advantages over only one or two men, because as the work is fatiguing, the men can undertake it in turns; and, again, as considerable knack is required for success, it is much more probable that one man out of many should succeed, than that only one man, taken at hazard, should do so.  But the best plan of all for a party of three or more men is for one of them to hold the upper block, another to hold the lower block and the tinder, should there be any, and the third man to cause the drill-stick to rotate.  He will effect this best by dispensing with the “bow,” and by simply using a string or thong of a yard or four feet long.  He makes one or two turns with the string round the drill-stick, and then holding one end of the string in either hand, he saws away with all his force.  I believe that a party of three men, furnished with dry wood of an appropriate quality and plenty of string, would surely produce smoke on the first few trials, but that they would fail in producing fire.  If, however, they had a couple of hours’ leisure to master the knack of working these sticks, I think they would succeed in producing fire before the end of that time.  The period of time necessary for a successful operation is from one to three minutes.  It is of little use fatiguing yourself with sustaining the exertion for a longer period at a time, unless the wood becomes continuously hotter.  As soon as the temperature remains uniform it shows that you have let the opportunity slip; it is then the best economy of effort to desist at once, to rest, to take breath, and recommence with fresh vigour.

[Sketch unlabelled].

Fire by Chemical Means.—­It is not in the province of this book to describe the various matches that take fire by dipping them into compositions; and I have already spoken of lucifer-matches in the last section.  Only one source of fire remains to be noticed, it is—­

Spontaneous Combustion.—­It is conceivable that the property which masses of greasy rags, and such-like matter, possess of igniting when left to themselves, might under some circumstances, be the only means available to procure fire.  It is at all events well that this property should be borne in mind when warehousing stores, in order to avoid the risk of their taking fire.  Any oil mixed with a hatful of shavings, tow, cotton, wool, or rags, heaped together, will become very hot in one, two, or more days, and will ultimately burst into flame.  The rapidity of the process is increased by warmth.