Part 83 (1/2)
”Thus fullers and dyers find that black cloths, of equal thickness with white ones, and hung out equally wet, dry in the sun much sooner than the white, being more readily heated by the sun's rays. It is the same before a fire; the heat of which sooner penetrates black stockings than white ones, and is apt sooner to burn a man's s.h.i.+ns. Also beer much sooner warms in a black mug set before the fire, than in a white one, or in a bright silver tankard.
”My experiment was this: I took a number of little square pieces of broad cloth from a tailor's pattern-card, of various colours. There were black, deep blue, lighter blue, green, purple, red, yellow, white, and other colours, or shades of colours. I laid them all out upon the snow in a bright suns.h.i.+ny morning. In a few hours, (I cannot now be exact as to the time,) the black being warmed most by the sun, was sunk so low as to be below the stroke of the sun's rays; the dark blue almost as low, the lighter blue not quite so low as the dark, the other colours less as they were lighter; and the quite white remained on the surface of the snow, not having entered it at all.
”What signifies philosophy that does not apply to some use? May we not learn from hence, that black cloths are not so fit to wear in a hot sunny climate, or season, as white ones; because, in such clothes the body is more heated by the sun when we walk abroad, and are at the same time heated by the exercise, which double heat is apt to bring on putrid dangerous fevers?--that soldiers and seamen, who must march and labour in the sun, should, in the East or West Indies, have a uniform of white?--that summer hats for men or women, should be white, as repelling that heat which gives head-achs to many, and to some the fatal stroke that the French call the _coup de soliel_?--that the ladies' summer hats, however, should be lined with black, as not reverberating on their faces those rays which are reflected upwards from the earth or water?--that the putting a white cap of paper or linen, within the crown of a black hat, as some do, will not keep out the heat, though it would if placed without?--that fruit-walls being blackened, may receive so much heat from the sun in the day-time, as to continue warm, in some degree, through the night, and thereby preserve the fruit from frosts, or forward its growth?--with sundry other particulars, of less or greater importance, that will occur from time to time to attentive minds?”
_Thirty Soldiers having deserted, so to place them in a Ring, that you may save any Fifteen you please, and it shall seem the Effect of Chance._
This recreation is usually proposed thus: Fifteen Christians and fifteen Turks being in a s.h.i.+p at sea, in a violent tempest, it was deemed necessary to throw half the number of persons overboard, in order to disburden the s.h.i.+p, and save the rest; to effect this, it was agreed to be done by lot, in such a manner, that the persons being placed in a ring, every ninth man should be cast into the sea, till one half of them were thrown overboard. Now, the pilot, being a Christian, was desirous of saving those of his own persuasion: how ought he therefore to dispose the crew, so that the lot might always fall upon the Turks?
This question may be resolved by placing the men according to the numbers annexed to the vowels in the words of the following verse:--
_Po-pu-le-am Jir-gam Ma-ter Re-gi-na fe-re-bat._ 4 5 2 1 3 1 1 2 2 3 1 2 2 1
from which it appears, that you must place four of those you would save first; then five of those you would punish. After this, two of those to be saved, and one to be punished; and so on. When this is done, you must enter the ring, and beginning with the first of the four men you intend to save, count on to nine; and turn this man out to be punished; then count on, in like manner, to the next ninth man, and turn him out to be punished; and so on for the rest.
It is reported that Josephus, the author of the Jewish History, escaped the danger of death by means of this problem; for being governor of Joppa, at the time that it was taken by Vespasian, he was obliged to secrete himself with thirty or forty of his soldiers in a cave, where they made a firm resolution to perish by famine rather than fall into the hands of the conqueror; but being at length driven to great distress, they would have destroyed each other for sustenance, had not Josephus persuaded them to die by lot, which he so ordered, that all of them were killed except himself and another, whom he might easily destroy, or persuade to yield to the Romans.
_Three Persons having each chosen, privately, one out of three Things,--to tell them which they have chosen._
Let the three things, for instance, be a ring, a guinea, and a s.h.i.+lling, and let them be known privately to yourself by the vowels _a_, _e_, _i_, of which the first, _a_, signifies one, the second, _e_, two, and the third, _i_, three.
Then take 24 counters, and give the first person 1, which signifies _a_, the second 2, which represents _e_, and the third 3, which stands for _i_; then, leaving the other counters upon the table, retire into another room, and bid him who has the ring take as many counters from the table as you gave him; he that has the guinea, twice as many, and he that has the s.h.i.+lling four times as many.
This being done, consider to whom you gave one counter, to whom two, and to whom three; and as there were only twenty-four counters at first, there must necessarily remain either 1, 2, 3, 5, 6, or 7, on the table, or otherwise they must have failed in observing the directions you gave them.
But if either of these numbers remain, as they ought, the question may be resolved by retaining in your memory the six following words:--
_Salve certa anima semita vita quies._ 1 2 3 5 6 7
As, for instance, suppose the number that remained was 5; then the word belonging to it is semita; and as the vowels in the first two syllables of this word are _e_ and _i_, it shews, according to the former directions, that he to whom you gave two counters has the ring; he to whom you gave three counters, the gold; and the other person, of course, the silver, it being the second vowel which represents 2, and the third which represents 3.
_How to part an Eight Gallon Bottle of Wine equally between two Persons, using only two other Bottles, one of Five Gallons, and the other of Three._
This question is usually proposed in the following manner: A certain person having an eight-gallon bottle filled with excellent wine, is desirous of making a present of half of it to one of his friends; but as he has nothing to measure it out with, but two other bottles, one of which contains five gallons, and the other three, it is required to find how this may be accomplished?
In order to answer the question, let the eight-gallon bottle be called A, the five-gallon bottle B, and the three-gallon bottle C; then, if the liquor be poured out of one bottle into another, according to the manner denoted in either of the two following examples, the proposed conditions will be answered.
8 5 3 8 5 3 A B C A B C 8 0 0 8 0 0 3 5 0 5 0 3 3 2 3 5 3 0 6 2 0 2 3 3 6 0 2 2 5 1 1 5 2 7 0 1 1 4 3 7 1 0 4 4 0 4 1 3
_A Quant.i.ty of Eggs being broken, to find how many there were without remembering the Number._
An old woman, carrying eggs to market in a basket, met an unruly fellow, who broke them. Being taken before a magistrate, he was ordered to pay for them, provided the woman could tell how many she had; but she could only remember, that in counting them into the basket by twos, by threes, by fours, by fives, and by sixes, there always remained one; but in counting them in by sevens, there were none remaining. Now, in this case, how was the number to be ascertained?
This is the same thing as to find a number, which being divided by 2, 3, 4, 5, and 6, there shall remain 1, but being divided by 7, there shall remain nothing; and the least number, which will answer the conditions of the question, is found to be 301, which was therefore the number of eggs the old woman had in her basket.