Equator being thus about

of the average surface gravity of the Earth, it will be then that the centrifugal tendency of the Earth's rotation accounts for only about two-thirds of that dif ference, or of the Earth's surface gravity, the remainder being supposedly due to the comparative nearness of the polar surface to the Earth's center, as evidenced by the fact that at any particular place, aside from the small irregular variations alluded to, the value of g depends upon the cosine of the latitude and the elevation with respect to sea level. It seems worse than a waste of time, therefore, to puzzle our brains with the possible or imaginary effects of partially unknown, or ever any factors, to modify the value of gravity when that value at any particular place is already known from actual observation. In fact, the problem, reduced to its simplest terms, consists of only four elements: A rigid plane fixed parallel to the ocean level of any place (that is, at a poleward slope, or inclination, or 11 feet in the mile to the plane tangent to the concentric spherical surface at the place), a perfectly round ball placed upon the plane, the actual attraction of gravity at that place (as determined by accepted observation) pulling the ball toward the Earth's center (and therefore directly poleward), and the centrifugal tendency generated by the Earth's rotation at that place urging the ball indirectly equatorward; to find the direction in which, according to the theory of gravita. tion, the ball should roll upon the plane.

The fact that gravity does not everywhere pull the ball directly toward the Earth's center, which is mathematically mag. nified by many geodesists, is entirely irrevelant to the problem. To ask how the ball upon the given plane could be urged in any direction by gravity when the action of gravity is everywhere vertical to the plane, is simply to beg the question. For the question is, How is it that, according to theory, the given plane came into its present inclination with respect to the Earth's center? The center of the Earth is also its center of gravity, and therefore should be its gravitative center. Indeed, it is so at those points of the Earth's surface where gravity is not laterally interferred with by the centrifugal tendency of rotation. It is this tendency which inclines the ocean level from the spherical surface. And it is generally admitted that, if this tendency were absent, the ocean level would everywhere be a spherical surface. This is clearly indicated, if not indeed proved, by the observed fact that, aside from occasional and comparatively insignificant variations of gravity (chiefly at oceanic islands), the values of gravity and of the centrifugal tendency both vary at the sea level as the cosine of the latitude

alone the first inversely and the other directly, because their actions are directly opposed to each other.

Therefore, the problem may be still more briefly and simply stated as follows: Find the effect of the present rotation of the earth upon the surface of its hydrosphere, which, if that rotation were absent, would have a spherical form.

But, as we have just seen, the rotation of the Earth accounts for littte more than half of the present variation of the Earth's surface from the spherical form; the average effect of rotation being 202, while the actual oblateness of the Earth, considered as due to that effect, is such as requires it to be 400.

It would seem, therefore, that since the mobile waters of the ocean do not conform to the requirements of the theory of gravitation and the effects of rotation, something must be wrong with the theory. If, not only the Mississippi River, but also the whole hydrosphere of the Earth, runs counter to it, it is quite evident the theory will not hold water!

And it seems just as obvious also that it is not a sufficient answer to this, to say as one or two eminent authorities have recently endeavored to impress upon the writer) that this problem has been settled for the past half century by the ablest mathematicians; one reason for its insufficiency being that these mathematicians, to obtain their results, have employed several factors the relevancy of which is questionable, and one at least even the value of which is still wholly unknown.

This problem is surely of sufficient importance to deserve the attention of both the teacher and the student of nature. It is also totally obvious that the rational solution of it is not so entirely in accordance with present views as most of the teachers of the subject suppose. This paper is written in the hope that the intelligent reader, whether teacher or student, in whose hands it may be placed, will take up the discussion of the problem, without prejudice from previous authority or prestige, and so keep it up until finally settled in the interest of truth and intellectual progress alone.

In the words of Faraday, with which we began, "The philosopher should be a man willing to hear every suggestion, but determined to judge for himself. He should not be biased by appearances, have no favorite hypothesis, be of no school, and in doctrine have no master. He should not be a respecter of persons, but of things. Truth should be his primary object." For varily it is only through the possession of these characteristics, together with a zealously active industry favoring them, that the human race may ever hope to walk within the veil of the temple of Nature. The Anglo-American Magazine.

How to Find the Constellations. II.

BY GEORGE I. HOPKINS.

If the observer has watched closely the movements of the two constellations already located, he must have noticed, not only that they make a complete circuit about Polaris every twenty-four hours, but also that they arrive at any particular position about four minutes earlier every evening; so that he will find them in nearly the same positions on the first of August about eight o'clock, that he did a month before at nine o'clock. But as it is not yet quite dark enough at eight to make out the stars plainly we will continue to make our observations at nine.

Let the observer now direct his gaze at Polaris as the starting point, and then he can quite readily follow a line of stars curving upward and to the left until a quadrant has been described, when he will see a pair of stars of about the third magnitude. Following the curve back a little way, he will see two other stars, fainter than the rest, but so situated that, with the pair above mentioned they form an oblong parallelogram. This is the bowl of the Little Dipper, the handle being the curve of which Polaris is the end. This is the principal group of stars in the constellation Ursa Minor, or Little Bear, which contains in all twenty-four stars.

There is a beautiful mythological story relating to Ursa Major and Ursa Minor, which runs as follows: The majestic and beautiful queen of Mt. Olympus became jealous of Diana's beautiful attendant Callisto, and changed her into a bear. Some time afterwards her son Arcus, while out hunting, pursued her, unaware that she was his mother, and was about to transfix her with his spear, when Jupiter, out of deep pity, immediately transferred them both to the heavens and placed them among the constellations, as the Great Bear and Little Bear, where

he continues to pursue her around Polaris without overtaking her.

If the observer will now face the southwest and direct his gaze upward rather more than half way from the horizon to the zenith he will see a bright star with a decided yellowish tint. This is the star Arcturus and is the only single yellow star visible to the naked eye. It is the brightest star in the constella tion Bootes (three syllables) and serves to mark its position. About half way from Arcturus to the zenith may be seen a number of stars in the form of a spiral and diminishing in bright ness as the spiral is traced. This is the celebrated Northern Crown the brightest star of which is Alphacca.

About fifteen degrees east of the zenith may now be seen a star of the first magnitude, perhaps the brightest of all now visible. This is the star Vega. Near it may be seen two others of about the third magnitude, the three forming an equilateral triangle. This the most prominent group in the constellation Lyra, the harp. It is an interesting fact that one of these lesser stars in a small telescope is seen to be a double star, while in a large telescope each component is itself seen to be also double, so that it is spoken of by astronomers as the double double star.

"And next Bootes comes whose ordered beams
Presents a figure driving of his teams,
Below his girdle, near his knees, he bears
The bright Arcturus, fairest of the stars.
Behind his back the radiant crown is view'd,
And shines with stars of different magnitude;
One placed in front above the rest displays
A vigorous light, and darts surprising rays.
This shone since Thesus first his faith betrayed,
The monument of the forsaken maid.

Nor far from these distended Lyra lies,

Well strung, the sounding glory of the skies.

This Orpheus struck when with his wondrous song
He charmed the woods, and drew the rocks along;
When Hell obeyed, when Death resigned her chain,
And loosed his dear Eurydice again.

This gained it Heaven, and still its force appears,

And then the rocks it now draws on the stars.

The planets dance, and to the tuneful sound

The Heaven consents, and moves the fatal round.”—Manilius.

Ben Lomond. Scotland's Finest Mount.

BY GEORGE BANCROFT GRIFFITH.

The black clouds parted, the rain was o'er,
Ben Lomond's summit was seen once more;
Lo! its glittering sheen was reflected bright
Where the miniature cascades flashed in sight.

On the mountain sides gushed myriad streams
With flaky masses and diamond beams,
And the waters coursing and leaping down
Swept the mists away and the morning's frown.

And the Grampian peaks from east to west
Shone out as if by the sun-god blessed;

All greet Ben Lomond, the long-crowned height,
And Argyleshire's hills, green domes of delight.

INSCRIBED TO BOOK BORROWERS. Sam Taylor, Clayton, Mass., has found it prudent to remind borrowers of his books that both the owner and subsequent borrowers have rights that should be respected. He exhorts, in printed slips, in verse, inserted in each book when loaned, as follows:

This book I lend to give you pleasure,
To read and ponder at your leisure,
To steal it would be mean.

Turn down no leaves, but treat it well,
Who next may read it, none can tell,
So please to keep it clean.
"Tis lent to you for your own perusal,
So please to give a quick refusal

To those that would it borrow.
Your pleasure sated, let it be
Promptly returned agained to me,
And thereby keep from sorrow

Yours truly, SAM TAYLOR.

THE VOYAGE OF ULYSSES. The several stages according to Gladstone, were:

1. The Land of the Lotophagoi. 2. Land of the Kuklopes. 3. Island of Aiolos. 4 The Laistrugoniè. 5. Aiaiè, the Island of Kirké. 6. The Underworld. 7. Aiaiè, on his return. 8. Island of Thrinakiê. 9. Ogugie, the island of Kalupso. 10. Scheriè, the land of the Phaiakes.