As I reflected thus, I grew a little uneasy as to the quantity both of my food and drink; and to put an end to all doubt upon the subject, I came to the above determination of measuring them. I recognised the prudence of such a course. If it turned out that there were plenty of both, and to spare, I should no longer be troubled with doubts; and if, on the other hand, there was a danger of either running short, I should then adopt the only precaution possible, and at once put myself on _short rations_! When I look back, and think of my cunning at this early age, I am now astonished at it; but it is surprising what forethought even a child will exhibit, when placed in circumstances where self-preservation calls forth all its instincts and energies. Without more ado, then, I proceeded to make my calculation. I allowed for time, the full six months; or in other terms, a period of 183 days. I did not even subtract the time--about a week, since we had set sail. That I set aside to my advantage, allowing the full period of 183 days, lest I might err by making the time too short. Surely, in six months, the vessel would reach her port, and her cargo be discharged? Surely, I might depend upon this? No, not surely. I was far from being confident on this head. I knew that a voyage to Peru was usually reckoned a six months' voyage; but I was not certain whether this was considered the average time; whether it would be accounted a long voyage or a short one; and, therefore, I had no confidence in basing my calculation on such uncertain data. There was the danger of delay from calms in the tropical latitudes, through which we should have to pass--from storms off Cape Horn, renowned among mariners for the fickleness of its wind--other obstacles might be encountered, and the voyage protracted far beyond the period above mentioned. I was not without such apprehensions, as I proceeded to examine my resources. To ascertain how long my stock of food would last, was simple and easy. I had only to count the biscuits, and find out their number. I knew their size, and that I could live on two a day, though I was not likely to grow fat on the allowance. Even one a day, or still less than that, would sustain life; and I resolved to be as sparing of them as I could. I soon ascertained the exact number. The box, as nearly as I could guess, was about a yard long and two feet wide, by about one foot in depth; for I noticed that it was a shallow one set upon its edge. Had I known its exact dimensions, I could have told the number of biscuits without counting them. Each was a little less than six inches in diameter, and of an average thickness of three-fourths of an inch. Therefore, packed as they had been, there would be exactly 32 dozen in the case.