Sirius is a comparatively young star, and is estimated by Proctor to have a diameter of about twelve million miles or fourteen times that of our own sun; it is only eight and one-half light-years away from us and is the most celebrated star in literature. The ancients knew it, the Egyptians worshipped it, Homer sang of it, and it has had its place in the poetry of all ages.

Procyon, (pro'-se-on) the Little Dog Star, was so-called perhaps because it trots up the eastern skies a little ahead of the magnificent Great Dog Star; it gives out eight times

as much light as our sun, and is only ten light-years away from us. fainter companion about three or four degrees to the northwest of it.

LESSON CCXXIX

THE TWO DOG STARS

It has a

Leading thought-The Great Dog Star, Sirius, is the most famous of all stars in the literature of the ages. The Two Dog Stars were supposed by the ancients to be following the great hunter, Orion.

Method-Draw upon the board from the chart shown on this page, the constellation of Orion with Sirius and Procyon. Ask the pupils to note that after Orion is well up in the sky a straight line drawn through Orion's belt and dropping down toward the eastern horizon ends in a beautiful white star, which is Sirius. And that if we draw a line from Betelgeuse to Rigel from Rigel to Sirius and then draw lines to complete a quadrangle, we shall find our lines meet at a bright star just a little too far away to make the figure a square, but making it somewhat kite-shaped instead. This is the Little Dog Star, Procyon, and it has a twin star near it. After giving these directions let the children make the following observations:

I. How do you find Sirius? Which rises first, Orion or Sirius?

2.

What color is Sirius? Judging from its color what stage of development do you think it is in?

3.

Try and find out how large Sirius is compared with our sun and how near it is to us.

4.

Why is Sirius called the Great Dog Star? Is the Little Dog Star nearer to the North Star than Sirius? Which is the brighter, the Great Dog Star or the Little Dog Star? Can you see any fainter star near Procyon?

5. Why is Procyon called the Little Dog Star?

6.

Make a chart showing Orion and the two Dog Stars.

CAPELLA AND THE HEAVENLY TWINS
Teacher's Story

Capella is nearer to the North Star than any other of the bright stars and it comes very near belonging to the strictly polar constellations, since it falls below the horizon only four hours out of twenty-four. In composition it much resembles our sun, as do all the bright yellow stars; but it is much larger; it gives off one hundred and twenty times as much light as our sun, and it is forty light-years away from us. Capella is always a beautiful feature of the northern skies, being almost in the zenith during the evenings of January and February. It is in a brilliant shieldshaped constellation known as Auriga.

During the winter evenings we see two stars set like glowing eyes almost in the zenith, and in a region of the sky where there are no other bright stars. These twin stars are set just a little closer together than are the pointers of the Big Dipper. To this brilliant pair the ancients gave the names of Castor and Pollux. Pollux is the brighter of the two and is the more southward in situation. Pollux and Castor were two beautiful twin boys who loved each other so much that, after they were dead, they were placed in the skies where they could always be near each other. The twin stars are supposed to exert a benign influence on oceans and seas and are, therefore, beloved by sailors. Although they seem to us so near together, they are separated by a space so great that we cannot conceive of it and they are going in opposite directions.

Gemini, the heavenly twins, the larger one is Pollux and the other is Castor.

Pollux is a yellow star, and supposed to be in the same stage of development as our sun, while Castor is white and according to star ages is young. When a boy says "By Jimminy," he does not realize that he is using an ancient expletive "By Gemini," which is the Latin name of these twin stars and was a favorite ancient oath, especially of sailors.

LESSON CCXXX

CAPELLA AND THE HEAVENLY TWINS

Leading thought-There are, during the evenings of January and February, three brilliant stars almost directly overhead. One of these is Capella, the other two are the Heavenly Twins.

Method-Place on the board the part of the chart (p. 895) showing the Big Dipper, Pole-star, Capella and the Twins. Draw a line, L, from the pointers of the Big Dipper, and extend it to the Pole-star. Draw another line, K, from the Pole-star at right angles to the line L, and on the side away from the Big Dipper's handle, and it will pass through a large, brilliant, yellow star which is Capella. Ask the pupils to imagine similar lines drawn across the sky, when they are making their observations and thus find these stars, and to place them on their charts, making the following observations:

1. What color is Capella, and how does its color compare with that of our sun?

2. Is Capella as near to the Pole-star as the Big Dipper? Is it near enough so that it never sets?

3. Can you see the shield-like constellation of which Capella is a part? Do you know the name of this constellation?

4. How do you find the Heavenly Twins after you have found Capella? 5. Why are these stars called the Heavenly Twins? What is their Latin name? What are the names of the two stars? Are these twins set nearer together than the pointers of the Big Dipper?

6. How can you tell the Heavenly Twins from the Little Dog Star and its companion?

7. Read in the books all that you can find about the Heavenly Twins. Try and find if they are the same age, if they are as near together as they seem, and if they are going in the same direction. What did the ancient sailors think of these twin stars?

THE STARS OF SUMMER

To us, who dwell in a world of change, the stars give the comfort of abidingness; they remain ever the same to our eyes and the teacher should make much of this. When we once come to know a star, we know exactly where to find it in the heavens, wherever we may be. A star which a person knows during childhood will, in later life and in other lands, seem a staunch friend and a bond, drawing him back to his early home and associations.

A chart of the brightest stars of summer, showing their positions in early evenings of June. To find the stars hold the chart above the head and face the north.

The summer is an enticing season for making the acquaintance of eight of the fifteen brightest stars visible in northern latitudes. Few midsummer entertainments rival that of lying on one's back on the grass of some open space which commands a wide view of the heavens, and there with a planisphere and an intermittently lighted candle with which to consult it, learn by sight, by name and by heart those brilliant stars which will ever after meet with friendly greeting our uplifted eyes. To teach the children in a true informing way about the stars, the teacher should know them, and nowhere in nature's realm is there a more thought-awakening lesson.

LESSON CCXXXI

THE BRIGHT STARS OF SUMMER

Leading thought-The stars which we see shining during summer evenings are not the same ones that we see during the winter evenings, except those in the polar constellations. There are eight of the brilliant summer stars, which we should be able to distinguish and call by name.

Method-Begin by the middle of May when the Big Dipper is well above the Pole-star in the early evening, and when, therefore, Regulus, Spica, Arcturus and the Crown are high in the sky. The others may be learned in June, although July is the best month for observing them. In teaching the pupils how to find the stars, again instruct them how to draw an imaginary straight line from one star to another and to observe the angles made by such lines connecting three or four stars.

Place upon the blackboard the figures from the chart (page 901), as indicated, leaving each one there until the pupils have observed and learned it. Then erase and place another figure. In each case try to get the pupils interested in what we know about each star, a brief summary of which is given. Note that the observations given in the lessons are for early in the evenings of the last of May, of June, and of early July.

Regulus (reg'-u-lus)

Draw upon the blackboard from the chart (p. 901) the Pole-star, the Big Dipper, the line G and the Sickle shown just below the outer end of the line. Extend the line that passes through the pointers of the Big Dipper to the North Star backward into the western skies; just west of this line lies a constellation called the Sickle, and the stars that form it outline this implement. The Sickle has a jewel at the end of the handle, which is a white and diamond-glittering star called Regulus. It is a great sun giving out one thousand times as much light as our own sun, and this light reaches us in about one hundred and sixty years. The Sickle is part of a constellation called the Lion, and from which comes the shower of meteors which we see on the evening of November 13th. Regulus is seen best in Spring.

Regulus, the large star in the handle of the sickle.

Arcturus (ark-tu'rus)

Place on the blackboard the Big Dipper, the Pole-star and the line E, Arcturus and the Crown. Extend the handle of the Big Dipper fol

is supposed to be one of the largest of all the suns, having a diameter of several millions of miles. During the latter part of June and July it is almost overhead in the early evening.

The North

ern Crown.

The Crown

Between Arcturus and Vega, but much nearer the former, is a circle of smaller stars that is called the Northern Crown, and which because of its form is quite noticeable.

Spica (spi'-ka)

Place on the blackboard the Big Dipper, the Pole-star, the line F and Spica. To find Spica draw a line through the star on the outer edge of the top of the bowl of the Big Dipper, through the star at the bottom of the bowl next the handle, and extend this line far over to the southwest, during the evenings of June and July. (See page 901) In August, this star sets at ten o'clock. Spica is a white star, and is the only bright one in that part of the sky. It is so far away from us that the distance has never been measured. Spica is in the constellation called the Virgin.

Vega (vee'-ga)

Place on the blackboard the Pole-star, the Big Dipper, the lines H and I and Vega with her five attendant stars, as shown in the chart. Teach that these stars are the chief ones in the constellation called The Lyre. To find Vega, draw a line from the Pole-star to the star in the Big Dipper which joins the bowl to the handle. Then draw a line at right angles to this (see chart lines H, I) and extend the line I a little farther from the North-star than is the end star of the Dipper handle; this line will reach a bright star, bluish in color, which can always be identified by four smaller attendant stars which lie near it and outline a parallelogram with slanting ends. Vega is the most brilliant summer star that we see in the northern hemisphere. It is a very large sun, giving out ninety times as much light as our sun; it is so far away that it requires twenty-nine years for a ray of light to reach us from it. Vega's chief interest for us, aside from its beauty, is that toward it our sun and all its planets, including our earth, are moving at the rate of thirteen miles per second.