doubtful, some twenty years back, by the experi- descent of the rack being uniform, the platinum ments of Despretz, has been recently proved to be wire is, of course, carried through the 360th part altogether incorrect by Regnault, who has con- of its range in each half-second, and a distinct firmed and extended the results of his predecessor. observation is given for each beat of the clock. The law, then, that gases occupy spaces in-If, therefore, an observer, stationed on the ground, versely as the pressures, not being the true expres- count the beats of a pendulum, beating in unison sion of the expansibility of gases, it follows necessarily that the ordinary formula based on this fictitious law, being merely empirical, cannot be expected to give results of great accuracy when applied to so delicate a question as the measurement of great heights.

with the balloon clock, and likewise note the instant at which the needle of the galvanometer is deflected, the temperature marked by the thermometer in the car of the balloon may be readily deduced, and even if the rates of the chronometer vary, a correction for this can easily be made.

These difficulties are, however, not altogether insuperable, and it is hoped that they have been by this time surmounted; and when an extended series of observations made in this manner, under satisfactory circumstances, shall have been concluded, results of interest and importance will

Experiments with captive balloons have been in The practical difficulties attending these experpreparation for a considerable time, under the iments have been found to be so great, that superintendence of a committee composed of sev-although two or three years have elapsed since the eral of the most distinguished members of the appointment of the committee charged with the British Association. These experiments have making of these experiments, no report has yet been undertaken principally with a view to deter-been laid before the association. mine the law of the decrease of the temperature of the air at various elevations above the ground, but the apparatus employed can be readily applied to the wetbulb thermometer, now always used in hygrometrical observations. The balloon used, having but a small weight to carry, is very small, being only eighteen feet in diameter, and twenty-doubtless be obtained. The heights, however, to five feet high. An apparatus called a telegraphthermometer, the use of which is to telegraph to the observer the temperature of the air surrounding the balloon, is attached to the car, and corresponding observations of the temperature are made on the ground, where the observer is placed. The so-called telegraph-thermometer, which we believe is the invention of Professor Wheatstone, is an ingenious mechanical contrivance, of the nature of which the following description will give an idea.

By means of a small clock-movement, a vertical rack is made to ascend and descend regularly in six minutes, three minutes being occupied in the ascent, and three in the descent. To the rack is attached a platinum wire, which moves within the tube of a thermometer. This wire travels in its ascent and descent through a space equal to 28° of the thermometric scale, and may be adjusted so as to pass over any 28° of the range. The balloon is moored to the ground by a single cord, around which are wormed two copper wires carefully covered with silk. The extremity of one of these wires is in connection with the mercury in the bulb of the thermometer, and that of the other wire is connected with the wire carried by the rack. The two lower extremities of the wires are connected together on the ground, and in the wire whose end is connected with the mercury in the thermometer, a sensible galvanometer is placed, a single small voltaic circuit being introduced in the course of the other wire. Matters being thus arranged, so long as the platinum wire in the tube is not in contact with the mercury the needle of the galvanometer will not be deflected, but it will deviate from its zero point as soon as the contact takes place, and remain deflected until the contact is again broken. The clock beating half-seconds, and the ascent and

which these observations can be extended must of course be limited; and in repeating experiments such as those of M. Gay-Lussac, recourse must be had to a balloon unmoored, floating freely in the atmosphere, and capable of supporting the observer and his instruments. Such experiments are of se costly and hazardous a nature as to deter most private individuals from attempting them; and it is only under the auspices of the government, or such a body as the British Association, that we can hope for a series of balloon experiments, made with the necessary care, and under a sufficiently wide range of circumstances, to ensure the perfect safety of the employment of them in physics.

THE GREEK SLAVE.

THOU art no slave, albeit thy hands are bound.
I would we were, even as thou art, freed!
The insolent comment of the gazers round

Thy heart is poised too far away to heed.
The shade of sadness, o'er thy patience cast,
Neither accuses Heaven nor chides at man.
Thou waitest till this lot be over-past,

As only those whose hearts are holden, can.
Thy woman's beauty, robbed of sheltering vest,
Makes solitude in the rude market place,
As if a spirit stood there, manifest,

Vouchsafing to our eyes a perfect grace.
Thy head is bowed, but not with shame or fear.
The Present lays no iron hand on thee;
The Past, the Eternal Future, stand too near.
Motionless, fettered, naked, thou art free,
Clothed on with chastity; and waiting there,
The thing that God appointeth thou wilt bear,
Holy and lovely, as a lily stands

Bearing fresh dew from His baptizing hands.
NEW YORK, Feb. 10, 1848.

Daily Advertiser.

From the Examiner.

and out of such laughing talk the story springs. The Princess; a Medley. By ALFRED TENNYSON. It is to be of the character of the scene that surMoxon.* rounds them, and to suit the time and place. No poem should be judged decisively at a first But the story-tellers are sitting at a luncheon reading-but this new poem of Mr. Tennyson's "silver-set," among the old Gothic ruins in the least of all. It is cast in a form which few read-park; the broken statue of an old feudal ancestor ers will take kindly to. Nevertheless, let them is propped up nigh them, gayly enrobed with Lilia's read on-and again. It is not unsafe to begin with a little aversion, where love lies waiting for you.

silken scarf; on the lawn of the modern Greekbuilt mansion beyond, the members of the institute of the neighboring borough are holding happy holiday with their children, putting science into sport; and to suit all this, and take up the talk of college, what other than a Medley should the story be?

A princess is its heroine, and a prince who had been betrothed to her in childhood is supposed to tell it. The old regal fathers (a brace of kingly portraits very perfectly contrasting the easiness and the wilfulness of kings) have a compact that their children shall wed; but the girl opposes it as she approaches womanhood, prevails on her father to give her his summer palace and gardens on the border between the two kingdoms, and, penetrated with man's injustice and impelled by the counsels of two ladies of her court, has founded a college for women there, to redress past centuries of her sex's wrong. The prince's father, with help of some hundred thousand men, is for bringing her to the altar in "a whirlwind ;" but the prince, loving her already from her portrait, prefers with two companions to follow her, and try to win entrance to her college. They disguise themselves as girls, it being death for men to enter. All these details are charmingly given, and our dry summary does them no justice.

Not the least interesting question raised by this book is whether or not Mr. Tennyson has shown an advance of power. We think he has. No luckless poet has been more pelted with his laurels, but not always considerately. We are content that he should leave unsurpassed the mere verbal melody, the lyrical sweetness, of his first utterances in song; since he has far overpassed that circle of the sensuous which appeared to bound him at the first. His sense of the beautiful could never have been more luscious, gorgeous, delicate, than seventeen years ago; but it has become chastened, and is less alloyed. Mind and heart have come up with ear and eye. Enlarged views, increased knowledge, powers in all respects maturing, show the unwearied student. Take the versification of the poem before us, and (making allowance for some wilfully prosaic lines) say if all that in that respect has won most admiration for Mr. Tennyson be not here in sustained completeness. Sweetness and music have found variety and strength. The same instrument is giving forth a more quiet fulness and depth of sound. Thought, feeling, and expression, are balanced with happier and more finished results. Sometimes we object to what seems an echo from the days of Elizabeth's great men; but it is such only as could have reached us through a man of kindred greatness. We will not say that the poem is not irregular, even clumsy, in its structure; but it is... built of gold. Nor, whatever may be objected to its plan, can it be urged that the foundations are lofty and the erection mean. The poet has avoided that error. He lays down a very humble ground-work, with whatever ambition he may aspire to rise above it.

The poem is really what the poet calls it, a Medley; being a summer's tale told after the fashion of a Christinas game by a "set" of college students. Assembled in the summer vacation at

Then comes the action of the poem, and the grave sweet purpose that lies hidden beneath its burlesque peeps out and shows itself. Thus they find the head of the college:

at a board by tome and paper sat,
With two tame leopards couched beside her
throne,

All beauty compassed in a female form,
The princess; liker to the inhabitant
Of some clear planet close upon the sun,
Than our man's earth; such eyes were in her
head,

And so much grace and power, breathing down
From over her arched brows, with every turn
Lived thro' her to the tips of her long hands,
And to her feet."

an old English country house, the home of one of Nor is the stately grandeur of her welcome them, whose sister Lilia

unworthy of that picture of herself:

"We give you welcome: not without redound
Of fame and profit unto yourselves ye come,
The first fruits of the stranger: aftertime,
And that full voice which circles round the grave
Will rank you nobly, mingled up with me.'"'

Her two chief tutors are her two counsellors,
Lady Blanche and Lady Psyche. The first is a
dreadful old blue with a charming little daughter
Melissa:

(“A rosy blonde, and in a college gown
That clad her like an April daffodilly

(Her mother's color) with her lips apart,
And all her thoughts as fair within her eyes
As bottom agates seem to wave and float
In crystal currents of clear morning seas;")

A long melodious thunder to the sound
Of solemn psalms, and silver litanies,
The work of Ida, to call down from heaven
A blessing on her labors for the world."

-and the second is a pretty young widow with a-And so ends the college day.
babe "a double April old," who is in fact the
sister of one of the prince's companions. To her
lecture room the three (supposed) tall young
northern damsels are assigned, where

"Sat along the forms, like morning doves
That sun their milky bosoms on the thatch,
A patient range of pupils;"

amid whom they take their place, and listen to the
lecture. This, we are bound to say, is admirable.
Herschel, making allowance for disputed points in
the nebular theory, could not have beat Lady
Psyche at-

"This world was once a fluid haze of light,
Till toward the centre set the starry tides
And eddied into suns, that wheeling cast
The planets;'

nor is she less a match for a Whewell or a Sewell
when she runs with zest through "all the ungra-
cious past," and at each dark step of its ill-acted
history assails "the gray preeminence of man."
Still higher and higher with her theme she rises,
till it exalts her into a prophetess of that future
which they will have the power to make.

"Everywhere

Two heads in council, two beside the hearth,
Two in the tangled business of the world,
Two in the liberal offices of life,
Two plummets dropt for one to sound the abyss
Of science, and the secrets of the mind:
Musician, painter, sculptor, critic, more :
And everywhere the broad and bounteous earth
Should bear a double growth of those rare souls,
Poets, whose thoughts enrich the blood of the
world."

A classic lecture follows:

("Rich in sentiment,
With scraps of thundrous Epic lilted out
By violet-hooded doctors, elegies
And quoted odes, and jewels five-words-long
That on the stretch'd forefinger of all Time
Sparkle forever.")

And then comes Hall. You see them passing in
among the columns to dinner,

"Pacing staid and still By twos and threes, till all from end to end With beauties every shade of brown and fair, In colors gayer than the morning mist, The long hall glittered like a bed of flowers;" and after Hall you follow them to the gardens, seeing pictures of the evening idleness of each;

and then

"When day Drooped, and the chapel tinkled, mixt with those Six hundred maidens clad in purest white, Before two streams of light from wall to wall, While the great organ almost burst his pipes, Groaning for power, and rolling thro' the court

We cannot of course follow the story out in the same detail, but the reader must come with us or. a day's country excursion with the princess, who invites the three new students as a master might three freshmen to dinner. When they have reached a fitting spot they pitch their tent of satin,

("Elaborately wrought
With fair Corinna's triumph; here she stood,
Engirt with many a florid maiden-cheek,
The woman-conqueror; woman conquered there
The bearded vietor of ten-thousand hymns,
And all the men mourned at his side;")

—and after fruit and wine, music is called for, and
a maiden sings. The song is not pleasing to the
princess. Its luxurious sadness is not of heroic
temper, nor does its yearning affection sort with
college aspirations. But therefore is it the finer
manifestation of the poet's art. From out its
dreamy lingering music rises so much of the very
soul of gentleness and womanhood, that, in its
heavenly tenderness and sweetness, colleges and
professors fade far away. As a piece of writing
it is not to be excelled, even in the wonderful mel-
odies of Tennyson (unless it be by a pastoral on
Love's home which occurs at the close of the
poem):

"Tears, idle tears, I know not what they mean,
Tears from the depth of some divine despair
Rise in the heart, and gather to the eyes,
In looking on the happy autumn-fields,
And thinking of the days that are no more.
"Fresh as the first beam glittering on a sail,
That brings our friends up from the underworld,
Sad as the last which reddens over one

That sinks with all we love below the verge ;
So sad, so fresh, the days that are no more.
"Ah, sad and strange as in dark summer dawns
The earliest pipe of half awakened birds
To dying ears, when unto dying eyes

The casement slowly grows a glimmering square;
So sad, so strange, the days that are no more.
"Dear as remembered kisses after death,
And sweet as those by hopeless fancy feigned
On lips that are for others; deep as love,
Deep as first love, and wild with all regret;
O Death in Life, the days that are no more.

There

The discovery of the prince and his companions follows hard upon this, but we cannot dwell on its details. In the confusion which ensues he is the means of saving the life of the princess, but this in no respect abates her wrath and scorn. is flight and capture, and the offenders are threatened with death. Then comes upon the scene a has suddenly made descent upon the father of the counter-threatening from the prince's father, who princess; and exaggerated rumors, and fears of armed men, and numberless undistinguishable dreads, take possession of the college.