Daniel Pierce Thompson （b. 1193,d. 1868） was born at Charlestown,Mass.but soon removed with his father tVermont,where he lived until twenty years of age,on a farm. His means of schooling were most limited,but he was very ambitious and seized every opportunity. By his own efforts he earned enough money tcarry him through Middlebury College,where he graduated in 1820. He then went tVirginia as private tutor,and while there was entered at the bar. He shortly returned tVermont,and opened a law office in Montpelier. In time he was elected a judge,and later secretary of state. From his college days Mr. Thompson was a writer for the various magazines. Among his novels may be mentioned "Locke Amsden,the Schoolmaster," "May Martin,or the Money Diggers," "The Green Mountain Boys," and "The Rangers,or the Tory‘s Daughter."
1."Have you any questions task me in the other branches,sir?" asked Locke.
"Not many," replied Bunker. "There is reading,writing,grammar,etc.which I know nothing about;and as tthem,I must,of course,take you by guess,which will not be much of a guess,after all,if I find you have thought well on all other matters. Dyou understand philosophy?"
2."Twhat branch of philosophy dyou allude,sir?" "Tthe only branch there is."
"But you are aware that philosophy is divided intdifferent kinds;as,natural,moral,and intellectual1."
"Nonsense! philosophy is philosophy,and means the study of the reasons and causes of the things which we see,whether it be applied1Intellectual,treating of the mind.
ta crazy man’s dreams,or the roasting of potatoes. Have you attended tit?"
"Yes,ta considerable extent,sir."
3."I will put a question or two,then,if you please. What is the reason of the fact,for it is a fact,that the damp breath of a person blown on a good knife and on a bad one,will soonest disappear from the well-tempered1 blade?"
"It may be owing tthe difference in the polish of the twblades,perhaps." replied Locke.
4."Ah! that is an answer that don‘t gdeeper than the surface," rejoined Bunker,humorously. "As good a thinker as you evidently are,you have not thought on this subject,I suspect. It took me a week,in all,I presume,of hard thinking,and making experiments at a blacksmith’s shop,tdiscover the reason of this. It is not the polish;for take twblades of equal polish,and the breath will disappear from one as much quicker than it does from the other,as the blade is better. It is because the material of the blade is more compact2 or less porous3 in one case than in the other.
5."In the first place,I ascertained that the steel was,made more compact by being hammered and tempered,and that the better it was tempered the more compact it would become;the size of the pores being made,of course,less in the same proportion. Well,then,I saw the reason I was in search of,at once. For we know a wet sponge is longer in drying than a wet piece of green wood,because the pores of the first are bigger. A seasoned or shrunk piece of wood dries quicker than a green one,for the same reason.
6."Or you might bore a piece of wood with large gimlet holes,and another with small ones,fill them both with water,and let them stand till the water evaporated4,and the difference of time it would1Tempered,brought ta proper degree of hardness. 2Compact,closely and firmly united,solid,dense.3Porous,full of pores or minute openings.
4 Evaporated,passed off in vapor.take tdthis would make the case still more plain. Swith the blades: the vapor lingers longest on the worst wrought and tempered one,because the pores,being larger,take in more of the wet particles,and require more time in drying."
7."Your theory is at least a very ingenious1 one," observed Locke,"and I am reminded by it of another of the natural phenomena2,of the true explanation of which I have not been able tsatisfy myself. It is this: what makes the earth freeze harder and deeper under a trodden path than the untrodden earth around it? All that I have asked,say it is because the trodden earth is more compact. But is that reason a sufficient one?"
8."No," said Bunker,"but I will tell you what the reason is,for I thought that out long ago. You know that,in the freezing months,much of the warmth we get is given out by the earth,from which,at intervals3,if not constantly,tsome extent,ascend the warm vapors tmingle with and moderate the cold atmosphere above.
9."Now these ascending streams of warm air would be almost wholly obstructed by the compactness of a trodden path,and they would naturally divide at some distance below it,and pass up through the loose earth on each side,leaving the ground along the line of the path,ta great depth beneath it,a cold,dead mass,through which the frost would continue tpenetrate,unchecked by the internal heat,which,in its unobstructed ascent on each side,would be continually checking or overcoming the frost in its action on the earth around.
10."That,sir,is the true philosophy of the case,you may depend upon it. But we will now drop the discussion of these matters;for I am abundantly satisfied that you have not only knowledge enough,but that you can think for yourself. And now,sir,all I wish tknow further about you is,whether you can teach others tthink,which is1Ingenious,well formed,skillful.
2Phenomenon,whatever is presented tthe eye. 3Intervals,spaces of time.half the battle with a teacher. But as I have had an eye on this point,while attending tthe others,probably one experiment,which I will ask you tmake on one of the boys here,will be all I shall want."
"Proceed,sir," said the other.
11."Ay,sir," rejoined Bunker,turning tthe open fireplace,in which the burning wood was sending up a column of smoke,"there,you see that smoke rising,don‘t you? Well,you and I know the,reason why smoke goes upward,but my youngest boy does not,I think. Now take your own way,and see if you can make him understand it."
12.Locke,after a moment’s reflection,and a glance round the room for something tserve for apparatus1,took from a shelf,where he had espied a number of articles,the smallest of a set of cast-iron cart boxes,as are usually termed the round hollow tubes in which the axletree of a carriage turns. Then selecting a tin cup that would just take in the box,and turning intthe cup as much water as he judged,with the box,would fill it,he presented them separately tthe boy,and said,"There,my lad,tell me which of these is the heavier."
13."Why,the cart box,tbe sure," replied the boy,taking the cup,half-filled with water,in one hand,and the hollow iron in the other.
"Then you think this iron is heavier than as much water as would fill the place of it,dyou?" resumed Locke.
"Why,yes,as heavy again,and more too-I know it is," promptly said the boy.
14." Well,sir,now mark what I do," proceeded the former,dropping intthe cup the iron box,through the hollow of which the water instantly rose tthe brim of the vessel.
"There,you saw that water rise tthe top of the cup,did you?" "Yes,I did."
"Very well,what caused it tdso?"
15."Why,I know well enough,if I could only think: why,it is1Apparatus,utensils for performing experiments.because the iron is the heavier,and as it comes all around the water sit can‘t get away sideways,it is forced up."
"That is right;and now I want you ttell what makes that smoke rise up the chimney."
16."Why,-I guess," replied the boy,hesitating,"I guess,-I guess I don’t know."
"Did you ever get up in a chair tlook on some high shelf,sthat your head was brought near the ceiling of a heated room,in winter? and did you notice any difference between the air up there and the air near the floor?"
17."Yes,I remember I have,and found the air up there as warm as mustard;and when I got down,and bent my head near the floor tpick up something,I found it as cold as could be."
"That is ever the case;but I wish you ttell me how the cold air always happens tsettle down tthe lower part of the room,while the warm air,somehow,at the same time,gets above."
18."Why,why,heavy things settle down,and the cold air-yes,yes,that‘s it,I am sure-the cold air is heavier,and ssettles down,and crowds up the warm air."
"Very good. You then understand that cold air is heavier than the heated air,as that iron is heavier than the water;snow we will gback tthe main question-what makes the smoke gupwards?"
19."Oh! I see now as plain as day;the cold air settles down all round,like the iron box,and drives up the hot air as fast as the fire heats it,in the middle,like the water;and sthe hot air carries the smoke along up with it,just as feathers and things in a whirlwind. Well! I have found out what makes smoke gup-is n’t it curious?"
20."Done like a philosopher!" cried Bunker. "The thing is settled. I will grant that you are a teacher among a thousand. You can not only think yourself,but can teach others tthink;syou may call the position yours as quick as you please."