Part 14 (2/2)

What should you say to a stove, which, suht or day, in rain or sunshi+ne, amid the ice of the pole, or under the sun of the equator, was able to keep itself constantly in the same condition; neither hotter nor colder one ave it ivenfor whole days together? It would be worthy of a fairy tale, would it not? Yet the human body is a stove of this description

But this requires a little explanation

It is rather bold in me, you may think, to assert so freely, that all the year round, from one end of the earth to the other, the human body is never colder nor hotter than mine is, for instance, at this present ue: but the exact varieties of _more_ or _less_ are not so easy to measure, and especially not easy to remember, with reference to so many bodies, scattered over the face of the whole earth What may be warmth for one in one case,that the sao and inspect every part of the globe in succession, how could he possibly recall, while touching the body of a negro in Senegal, in July, the exact amount of animal heat he had found in a Greenland Esquimaux in January?

Be content I should not have settled the question so cavalierly, if people had not discovered an infallibleaccurately, and always in the saree of warmth, in other words, the _temperature_ of the body

Let us first see, then, what this ress a little; but you are accustoht ahead, you would not be able to followvery cold? Let irls as much as they please, to prevent it, it is sure to happen to every one some day or other Now does it not see itself--and when people are shi+vering with cold, have they not a shrunk, shrivelled look? When the weather is very hot, on the contrary, our bodies feel as if they were swelling and stretching, and one seems to take up more room than before This is the case with all bodies Heat swells, or, as learned people call it, expands, them: cold shrinks or contracts thes most susceptible of this action of heat and cold, and we have had recourse to it accordingly, in the construction of the _thermometer_, [Footnote: _Thermometer_ comes from two Greek words: _therrees in the Therrade_ principle [Not the one (Fahrenheit) in general use in the United States]] a very useful instrument, which you will hear spoken of all your life

The _thermometer_, or _heat-measure_, consists of a little hollow ball filled with lass, in which the mercury can move up and down When the thermometer is exposed to heat, the heat causes the oes up the tube; when the therain

Now suppose you were to er-tip of the other in a saucepan of boiling water; you would find a great difference of temperature between the tould you not? Which difference of te with the thermometer, as accurately as your mamma measures a piece of cloth with her yard measure

This is how it is done:

You surround the ball ofmake a mark at that point in the tube where the e the theroes up, up, up, till at last it reaches a point beyond which it will not pass Here a second mark is made, and the space between the two marks is divided into a hundred perfectly equal parts, indicated by so rees_ But this word _degrees_ has a double rees of , as you know, the perfectly equal parts into which a staircase is divided Fancy thefroarret where the boiling water is, and let it consist of 100 steps Theas the te water or of theice; and if you wish to know exactly how far it is froarret, you have only to count the _steps_ Hence arise those expressions which you so often hear--high temperature and low te to which the oes up or down this staircase

On the actual floor of the cellar where the ice rees (a floor is not a _step_, you know), so there you find the word _zero_, which in to count 1, 2, 3, 4 degrees, arret, _ie_ the boiling-water height

Of course, if the therreater than that ofice, the ly the staircase is carried below it, with steps (so to speak) of precisely the same size as those above, and you count as before, 1, 2, 3, &c, as it descends; adding however, to distinguish these degrees froo on in that way as far as 40; but there you must stop At that point the mercury freezes He sits down there on his last step, and will not go any further!

In the sareater than that of boiling water, the arret

So the staircase is her, and alith steps of the sa from 101 upwards, as far as 350 if you choose; but no further, observe! If the tein to boil, and then, indeed, good-bye to steps and entleman would dance so fast that there would be no possibility of seeing anything, to say nothing of his flying away!

Now nothing is easier than to use the thermometer You place it in the situation where you want to oes up or down of itself until it reaches the degree which corresponds with the temperature of the place It is much more convenient than your mamma's yard measure, which has to be moved about over the stuff, and which is very apt to slip if you do not hold it carefully Dresshted to have aupon the material, and which would unroll itself and stop short just at the proper point And this kind of office the thermometer really performs

We will suppose to-day to be the 30th of November I have just carried the thermometer out of doors; the ree _below zero_ This tells ers have told me so already; but exactly to what extent they could not say Just now in the rooree _above_ zero, thanks to the stove in which we have a good fire In surees I once saw it clirees: in the shade of course, you understand; in the sun it would have been quite another affair Well! there was a universal outcry against the heat Grown-up young ladies whos as I do you, pretended that it was ireater heat inside et the ther to make a hole in it: luckily there is one already I put the ball of mercury intoThe mercury was on its way up the staircase as soon as I took the ball in my hand--and now it has reached the 37th step

You can try the experiht to be rather hotter with you than with her I will not proree--but that will be all In different ree, rooo beyond these than a tethered cow can get beyond the circle made by her cord as she turns round the stake Go round the world with your ther it if you choose as you proceed, you will always find thecord is so else about us; but if by any accident it should exceed its liree above or below, it would be quite as extraordinary as ht feet, or a dwarf of three--which one does see occasionally, although the standard of huenerally round the centre of five feet

Since there is a fire always kept burning within us, there is no difficulty in co why our bodies always keep warhter in winter than in summer, but people have no need to be told so Nature provides for the necessity

She gives us more appetite in cold than in hot weather; not that we can perceive much difference in ourselves in this respect from winter to summer; for our bodies stick to their accustomed habits, and call out pretty loudly for the sa the same need of them In order to estimate fairly the connexion which exists between the internal need of food--_ie,_ of combustible matter--and the external temperature, we must compare the Hindoo, who lives on a pinch of rice a day, between the tropic and the equator, with the Esquirees of heat, beyond the polar circle, in a country where European travellers have seen mercury freeze, sometimes ss fro! Just fancy _whale-oil!_ which is much nastier than even cod-liver oil, if you ever tasted that; but, on the other hand, it is a thorough _combustible_, and the poor people are not so very particular: come ill, the firethus into extreal, the land of oranges, it is not uncoentlemen and ladies (that is to say, those who can eat and drink what they please) dine standing, in five minutes, on a bit of bread and whatever else may be handy Propose this system to the inhabitants of our colder and da ladies, fair and delicate-looking as they are, need a helping of good roast-beef for dinner to keep life in theh at you But those ell instructed could go on to inform you that the chilly atmosphere of northern countries creates the necessity for a more active internal fire than is ever needed under the burning sun of Portugal, and that a mouthful of bread per day will not, in their case, suffice to rees of heat

For the same reason, Spaniards drink water, and are satisfied; whereas English wine-n wines, or they would be quite unacceptable fro deficient in combustible

It is for the sa, buht: and that the Swedish Government has no end of trouble to keep the country people froo to the miller; whilst the Mohammedan Arabs accept without difficulty that precept of the Koran which forbids the use of wine and spirituous liquors It is easy for the Arabs, who are kept warm by their climate, to do without brandy It is less easy for the Swedes, who are surrounded by cold

All this co ourselves, without being unusually sagacious In January, when the therrees below zero, I putto-day, with only two degrees of cold to bear with There is nothing surprising in all this