And the muscles of his brawny arms
Are strong as iron bands.

2. His hair is crisp, and black, and long;
His face is like the tan;

His brow is wet with honest sweat;

He earns whate'er he can,

And looks the whole world in the face,
For he owes not any man.

3. Week in, week out, from morn till night, You can hear his bellows blow;

You can hear him swing his heavy sledge
With measur'd beat and slow,
Like a sexton ringing the village bell,
When the evening sun is low.

4. And children coming home from school
Look in at the open door;

They love to see the flaming forge,
And hear the bellows roar,

And catch the burning sparks that fly
Like chaff from a threshing-floor.

5. He goes, on Sunday, to the church,
And sits among his boys;

He hears the parson pray and preach,
He hears his daughter's voice,

Singing in the village choir,

And it makes his heart rejoice.

6. It sounds to him like her mother's voice, Singing in Paradise!

He needs must think of her once more,
How in the grave she lies;

And with his hard, rough hand he wipes
A tear out of his eyes.

7. Toiling, rejoicing, sorrowing,

Onward through life he goes;

Each morning sees some task begun,
Each evening sees it close,
Something attempted, something done,
Has earn'd a night's repose.

8. Thanks, thanks to thee, my worthy friend,
For the lesson thou hast taught!
Thus, at the flaming forge of life,
Our fortunes must be wrought;
Thus, on its sounding anvil, shaped
Each burning deed and thought.

PART VII.

SECOND DIVISION OF NATURAL PHILOSOPHY.

[This subject is continued from the Fourth Reader.]

1. "WELCOME to the hills and dales of Glenwild," said Mr. Maynard, as he met for the first time, after a short vacation, the Volunteer Philosophy Class, composed of Masters George, John, and Frank, and Misses Ida and Ella. "Welcome to the pleasant shade of the spreading oak, to the lawn, the grove, the meadow, 'The River;' but especially to the LIBRARY and recitation-room, endeared by the memories of the past, and where we hope to talk over the remaining topics of philosophy. But tell me first how you have spent the vacation."

2. After a short pause, John, who was the eldest of the class, replied that he had passed the brief month about his father's mill, where he had felt the advantage of the scientific knowledge he had gained, and his need of more.

3. George had contrived a new arrangement of levers to remove stumps of trees from his father's farm, and had also

made a whippletree in such a way that a weak horse could plow with a strong and able one without having to pull more than one third as much as the other.

4. Frank had passed his vacation in the city, but not unmindful of the lessons he had learned at Glenwild. His philosophical experiments had been principally confined to rowing and sailing; and the best possible rig for his boat was the subject to which his thoughts had been chiefly directed.

5. Ida and Ella had accompanied Mr. Maynard and his family in their vacation tour to Niagara, the Lakes, the White Mountains, and the sea-side. They had seen many practical illustrations of those laws of philosophy which they had already learned; and while they were not less delighted and enraptured with the sublime and picturesque objects of their visit than the most poetical tourists, they still had many questions to ask about rainbows, clouds, waves, and winds-phenomena which Mr. M. promised to explain more fully on their return to Glenwild.

6. Mr. Maynard told them that he well remembered his promise, and that the remaining departments of Natural Philosophy related to water, winds, clouds, rainbows, thunder and lightning, and other similar phenomena. It would not, however, be possible to give them all the instruction they would need on so many and important subjects in the time devoted to philosophy; but he had made arrangements to explain many things about them in a course of lessons on Physical Geography.

7. "We have to study matter," remarked Mr. Maynard, "in its three forms or conditions. All material substances are either solids, liquids, or gases. Many substances-perhaps all-may exist in all three of these forms, under proper conditions of temperature and pressure; as steam, which may be condensed into water or frozen into ice. Even metals may be melted, and then converted into vapor.

8. "There are two conditions or aspects in which all these forms of matter should be considered, viz., in a state of rest and in motion; the former of which is treated under the head of statics, and the latter under that of dynamics. The Lessons on Philosophy in the Fourth Reader were on the statics and dynamics of solids; and our present course will treat of the corresponding laws of liquids and gases.'

9. "I would like to ask," said Frank, "if the allotment of the empire of the world, in ancient mythology, to the three brothers, Jupiter, Neptune, and Pluto, had any reference to

the three forms of matter of which the world is composed."

"It is not improbable," replied Mr. Maynard, "that this distribution of authority by the ancients was their mysterious way of exhibiting the truth which seems so plain to us. Jupiter and his wife Juno had special direction of atmospherical phenomena, such as thunder and lightning, wind, clouds, snow, and rainbows. Homer says the portion which fell to Jupiter was the 'extensive heaven in air and clouds.'

10. "I recollect reading," said Frank, "that Jupiter was also called Zeus,1 and that in old times the expression, 'What is Zeus doing?' was equivalent to What kind of weather is it ?'"

6

"I would also remind you," continued Mr. Maynard, "that Neptune was the god of water in general, but especially of the sea, rivers, and fountains. Pluto's abode was in the solid earth; and his name, which in Greek means riches or wealth, indicates his supremacy over the solid forms of matter. Thus we see that Frank's question was quite appropriate; and the three forms of matter were evidently represented in this mystical manner by the wisest men of former times."

11. "I think," said Frank, "that they call rich men solid men in our day, which is most appropriate, as Pluto was the same as wealth, and had charge of the solid part of matter."

"I do not think the solid men will thank you for your etymological discovery," said Ida. "It is certainly more fanciful than philosophical," said Mr. Maynard, who then proceeded to assign the subject of HYDROSTATICS for the next lesson.

1 ZEUS, the Greek name for Jupiter, pronounced in one syllable, as zūs.

LES. II.—HYDROSTATICS, OR LIQUIDS IN A STATE OF REST. 1. Mr. M. As, in our lesson on the statics1 of solids, the knowledge of a few principles and definitions enabled you to solve many problems of apparent difficulty, so in the statics of liquids, or hydrostatics, you may expect to do the same by the same means. The first thing necessary is a definition of the term fluid.

2. Ida. I looked in Webster's Dictionary for a definition, and found it to be "any substance whose parts easily move and change their relative position without separation, and which yields to the slightest pressure."

3. John. Is not every thing fluid that is not solid?

Mr. M. Yes, every thing is either solid or fluid. Water and air are both fluids, but they are not both liquids. Will George define the term liquid?

4. George. I took pains to look in Webster's Dictionary also for the term. I found it to be " a fluid or flowing substance; a substance whose parts change their relative position on the slightest pressure, and which flows on an inclined plane." I can not understand from this the difference between a fluid and a liquid.

5. Mr. M. All liquids are fluids, but all fluids are not liquids. Those fluids which tend to expand when at liberty, as air and gases, retain their name, and are properly called fluids; but such as do not so expand are commonly called liquids, as water, oil, and mercury. Many phenomena show that both attractive and repulsive forces exist between the particles which compose the mass of a body. When the attractive force is predominant, the body is a solid. When the two forces balance, the body is a liquid; and when the repulsive force predominates, the matter is a gas. In the last-named case the particles tend apart, so that some external force is required to keep them together. It is very important to keep these distinctions in mind, if you would understand the appearances you will be called upon to explain. Will John now inform us what is the most noticeable property of water after its fluidity?

6. John. I think every person must have observed the level surface of water when it is at rest. I have often heard people talk of a water-level.

Mr. M. The earth, you know, is spherical, or nearly so; and as three fourths of its surface are covered with water, it is evident that the water-level conforms to the shape of the earth, which has a convex surface. This deviation from a plane, or a straight line, is found to be eight inches in one mile. Do you know what it would be for two miles? 7. Frank. I suppose it must be sixteen inches, and so on for any distance.

A

6000

h

4:000

4000

B

John. There must be some mistake here; for I once stood on the ice, and with a good spyglass I could see an object at the very water's edge, less than three miles distant.

8. Ella. If Frank is correct, in four Fig. 1, showing the varia- thousand miles, the straight line would vary from the earth's curvature only four

tion of the curve from the straight line A B.