is laid on the surface of the water, there is no chance left for it. I have sometimes seen the water covered with gnats which had perished thus as soon as they were born. It is, however, still more extraordinary that the gnat is able to finish its operations. Happily they do not last long; all dangers may be passed over in a minute.

12. The gnat, after raising itself perpendicularly, draws its two front legs from the sheath, and brings them forward. It then draws out the two next. It now no longer tries to maintain its uneasy position, but leans towards the water; gets near it, and places its feet upon it; the water is a sufficiently firm and solid support for them, and is able to bear them, although burdened with the insect's body.

13. As soon as the insect is thus on the water, it is in safety; its wings are unfolded and dried, which is done sooner than it takes to tell it: at length the gnat is in a position to use them, and it is soon seen to fly away, particularly if one tries to catch it.

LXXVI.—THE PONY-RIDER.

Figuier.

con'-ti-nent, one of the larger bodies of land; Festland.
hos'-tile, unfriendly; warlike; feindlich.

im-pa'-tient, restless; ungeduldig.

trans'-fer, removal; conveyance; Übertragung.

round'-a-bout, a jacket; Jacke.

su-per'-flu-ous, unnecessary; überflüssig.

be-lat'-ed, being too late; verspätet.

1. We were waiting for the pony-rider, the fleet messenger who sped across the continent from St. Joseph to Sacramento, carrying letters nineteen hundred miles in eight days, before the Pacific Railroad connected the East and the West.

2. The pony-rider was generally a little man, but brimful of spirit and endurance. No matter what time of the

day or night his watch came on, and no matter whether it was winter or summer, raining, snowing, hailing, or sleeting, he must always be ready to leap into the saddle and be off like the wind.

3. He rode fifty miles without stopping, by daylight, moonlight, starlight, or the blackness of a dark night; over a level road or through mountain wildernesses; through peaceful regions or regions infested with hostile Indians.

4. He rode a splendid horse, that was born for a racer and fed and lodged like a gentleman, kept him at his utmost speed for ten miles, and then, as he came rattling up to the station, where stood two men with a fresh, impatient steed, the transfer of rider and mail-bag was made in the twinkling of an eye, and away flew the eager pair and were out of sight in a few moments.

5. The rider's dress was thin and fitted close; he wore a roundabout and a skull-cap, and tucked his pantaloons into his boot-tops. He carried no arms, nothing that was not absolutely necessary.

6. His horse, too, was stripped of all superfluous weight; he wore a little racing-saddle, and no visible blanket; he wore light shoes, or none at all. The little flat mail-pockets would each hold about the bulk of a child's primer. They held many an important letter, but these were written on paper as airy and thin as it could be found, and the postage was five dollars a letter.

7. There were about eighty pony-riders in the saddle all the time, night and day, stretching in a long, scattering procession from Missouri to California, forty flying eastward, and forty toward the west.

8. We had had a burning desire to see a pony-rider, but. somehow they all passed us by night. But now we were expecting one along every minute, and we would see him in broad daylight. Presently the driver shouts :

"Here he comes!

9. Every neck is stretched further, and every eye seeks the distant horizon. Away across the endless dead level of the prairie a black speck appears against the sky, and it is plain that it moves. In a moment or two it becomes a horse and rider, rising and falling, rising and falling, sweeping nearer and nearer, growing more and more distinct. Now the flutter of the hoofs comes faintly to the ear, now nearer and clearer-another instant- a whoop from our company, a wave of the rider's hand, but no reply—and man and horse burst past our excited faces and go winging away like a belated fragment of a storm.

LXXVII.-WHAT THE AIR IS MADE OF.

in-vis'-i-ble, incapable of being seen; unsichtbar.

ma-te'-ri-al, bodily; körperlich.

en'-vel-ope, a wrapper; Umhüllung.

at'-mos-phere, the air surrounding the earth; Dunstkreis;

Atmosphäre.

ni'-tro-gen, a gaseous element; Stickstoff.

in-gre'-di-ent, a component part; Bestandteil.

par'-ti-cle, a small part; Teilchen.

im-por-tance, weight; consequence; Wichtigkeit.

car-bon ́-ic ac ́-id gas, a heavy gas; (one part of carbon and two of oxygen); Kohlensäure.

1. When we begin to look attentively at the world around us, one of the first things to set us thinking is the air. We do not see it, and yet it is present wherever we may go. At one time it blows upon us in a gentle breeze, at another it sweeps along in a fierce storm. What is this air?

2. Although invisible, it is yet a real, material substance. When you swing your arm rapidly up and down, you feel the air offering a resistance to the hand. The air is something which you can feel, though you can not see it. You breathe it every moment. You can not get away from it,

for it completely surrounds the earth.

To this outer en

velope of air the name of Atmosphere is given.

3. From experiments we learn that the air is not a simple substance, but a mixture of two invisible gases, called nitrogen and oxygen. But besides these chief ingredients, it contains also small quantities of other substances; some of which are visible, others invisible. If you close the shutters of a room, and let the sunlight stream through only one chink or hole into the room, you see some of the visible particles of the air.

4. Hundreds of little motes or specks of dust cross the beam of light which makes them visible against the surrounding darkness, though they disappear in full daylight. But it is the invisible parts of the air which are of chief importance; and among them there are two which you must especially remember-the vapor of water and carbonic acid gas. You will soon come to see why it is needful for you to distinguish these.

5. Now what is this vapor of water? You will understand its nature if you watch what takes place when a kettle boils. From the mouth of the spout a stream of white cloud comes out into the air. It is in continual motion; its outer parts somehow or other disappear, but as fast as they do so they are supplied by fresh materials from the kettle.

6. The water in the kettle is all the while growing less, until at last, if you do not replenish it, the whole will be boiled away, and the kettle left quite dry. What has become of all the water? You have changed it into vapor. It is not destroyed or lost in any way, it has only passed from one state into another, from the liquid into the gaseous form, and is now dissolved in the air.

7. Now, the air always contains more or less vapor of water, though you do not see it so long as it remains in the state of vapor. It gives rise to clouds, mist, rain, and

snow. If it were taken out of the air, everything would be dried up on the land, and life would be impossible. As you learn more and more of the changes which take place from day to day around you, you will come to see that this vapor of water plays a main part in them all.

8. Carbonic acid gas is also one of the invisible substances of the atmosphere, of which, though it forms no more than four parts in every ten thousand, yet it constitutes an important ingredient. You will understand how important it is, when you are told that, from this carbonic acid in the air, all the plants which you see growing upon the land extract nearly the whole of their solid substance.

9. When a plant dies and decays, the carbonic acid is restored to the air again. On the other hand, plants are largely eaten by animals, and help to form the framework of their bodies. Animals in breathing give out carbonic acid gas; and when they die, and their bodies decay, the same substance is again restored to the atmosphere.

LXXVIII. OUR FLAG.

peak, a point; Spike.

Science Primers.

hor-i-zon'-tal, parallel to the horizon; wagerecht.

frig'-ate, a war ship; Fregatte.

bunt'-ing, a thin cloth used for flags; Flaggentuch.
ver'-ti-cal, standing upright; senkrecht.

ap-pro ́-pri-ate, suitable; angemessen.

sym'-bol, an emblem; Symbol; Zeichen.

al-ly', a confederate; ein Verbündeter.

skir'-mish, a light combat; Scharmüßel.

pri-va-teer', armed private vessel; Kaper.

ap-peal', to call on one for aid; sich an jemand um Hilfe wenden. coat of arms; Wappen.

ac-knowl'-edge, to admit; anerkennen.

un-furl', to unfold; entfalten.

con-stel-la'-tion, a group of stars; Sternbild.

pluck, courage; Mut.