are marked at the top of the other columns; and hence, when the Sun's declination and the latitude of the place is known, the semi-duration of the Sun above the horizon, corresponding to these given quantities, is found in the column answering to the latitude, and in the line with the declination, and is expressed in hours and minutes. This expresses the time of his setting, or that which elapses between his passing the meridian and the moment of his sinking beneath the western horizon; and, consequently, if this be taken from 12 hours, it will give the time of his rising on the same day. The declination which is to be used is that answering to noon of the given day. As an example, Let it be required to find at what time the Sun will rise and set on the 15th of April, 1820, in latitude 50°, the place being situated on the first meridian. The declination of the Sun answering to the time of his passing the meridian on that day, taken to the nearest minute, is 9° 50' north; then looking in the first column for 9°, in the same line, and the column answering to the given latitude is 6h. 47 m. for the corresponding i time. But as there is 5 m. difference between the time answering to 9° and 10° of declination, gths of this must be added for the 50 m., which is 4 m. 10 s.; and, consequently, 6 h. 51 m. 10 s. will be the time of the Sun's setting on that day. Hence we also have 12 h. 6h. 51 m. 10 s. 5 h. 8 m. 50 s., or 8 minutes and 50 seconds past 5 in the morning, for the time of his rising.

Now it is evident, from the nature of these quantities, that double the time of his setting will be the length of his duration above the horizon, or the length of the day; and double the time of his rising will be the length of the night: in the present case the former is 13 h. 42m. 20 s., and that of the latter 10 h. 17 m. 40 s.

Again, Let it be required to find the time of the Sun's rising and setting at York, supposing it to be

in latitude 53° 58', on the 3d of August, 1820. In this case, neglecting the very slight variation in the Sun's declination between noon at the Royal Observatory and at York, the declination for that day will be 17° 30' north; and with 17°, and latitude 53°, we have, in the table of semi-diurnal arcs, 7 h. 40 m., to which 3 m. must be added for the 30′ of declination, and 4 m. for the 58' of latitude; and hence the time required is 7h. 50 m., which, taken from 12 h., gives 4 h. 10 m. for the time of his rising. These being doubled, also give 15 h. 40′ for the length of the day, and 8 h. 20 m. for that of the night.

If it were required to find the time of the Sun's rising and setting at Tobolsk, in Asiatic Russia, on the 1st of October, 1820, we should have the latitude of the place, taking the nearest minute, which is always sufficiently accurate in cases of this kind, 58° 12′ north, and the longitude 68° 6' east. Now the declination of the Sun, when he passes the first meridian of this country on the given day, is 3° 15′ south; and the change in the preceding 24 hours is 23′ 21′′; and therefore for the 4 hours, answering to the difference of longitude, 43' must be subtracted, since the longitude is east, and the declination increasing, which makes the declination of the Sun, when that luminary passes the meridian of Tobolsk, equal to 3° 10' south. Hence, by the table at page 43 of the Ephemeris, we have 5h. 45 m., corresponding to 3° of declination and 58° of latitude; to which 1′ 13′′ must be added for the 10' of declination, and 12′′ subtracted for the additional minutes of the latitude; and therefore the true time of the Sun's setting at Tobolsk, on the day proposed, will be 46 m. 1 s. after 5; and the time of his rising 13 m. 59 s. after 6.

Here it may be observed, that when the Sun is approaching the zenith of the observer, that is, in these northern latitudes proceeding from the tropic of Capricorn to that of Cancer (or the contrary, on the south side of the equator), any change in his decli

nation augments the length of the day; but as he recedes from that point, such a change diminishes: his duration above the horizon. On the other hand, an increase of latitude increases the length of the day, when the observer and the Sun are both on the same side of the equator; and diminishes, it when they are on contrary sides of that circle. The preceding examples illustrate these general precepts.

The Naturalist's Diary

For MAY 1820.

And now the young and flow'ry-kirtled MAY
Decks the green hedge and dewy grass unshorn,
With cowslips pale and many a whitening thorn;
And now the SUN comes forth with level ray,
Gilding the high wood-top, and mountain gray;
And, as he climbs, the meadows'gins adorn ;
The rivers glisten to the dancing beam,

Th' awakened birds begin their amorous strain,
And hill and vale with joy and fragrance teen.

BAMPFYLDE.

THIS month bright with sunshine, and fragrant with perfumes, covers the meadow with verdure and decks the gardens with all the mixtures of colorific radiance; a month from which the man of fancy draws new infusions of imagery, and the naturalist new scenes of observation. And yet there are some to whom these scenes are able to give no delight, and who hurry away from all the varieties of rural beauty, to lose their hours and divert their thoughts by a tavern dinner, the prattle or the politics of the day;or, to mix with a mass of people as insensible as themselves. Such is, with some exceptions, a LONDON MAY often,

Chilled by rude gales, while yet reluctant May
Withholds the beauties of the vernal day;
As some fond maid, whom matron frowns reprove,
Suspends the smile her heart devotes to love;
The season's pleasures too delay their hour,
And winter revels with protracted pow'r ;

What prudent cit dares yet the season trust,
Bask in his whisky, and enjoy the dust?
Housed in Cheapside, scarce yet the gayer spark
Achieves the Sunday triumph of the PARK;
Scarce yet you see him, dreading to be late,
Scour the New-Road, and dash thro' Grosvenor-gate.
Anxious and fearful too-his steed to show,
The hacked Bucephalus of Rotten-Row:
Careless he seems, yet vigilantly sly,
Wooes the stray glance of ladies passing by,
While his off-heel, insidiously aside,
Provokes the caper which he seems to chide.
Scarce rural Kensington due honour gains,
The vulgar verdure of her walk remains,
Where white-robed misses ramble two by two,
Nodding to booted beaux- How do ? how do?
With gen'rous questions, that no answer wait,
'How vastly full!' A'n't you come vastly late?
Is n't it quite charming? When do you leave town?
A'n't you quite tired? Pray, can we set you down?'

The latest species of the summer birds of passage arrive about the beginning of this month. Among these are the goatsucker, or fern-owl (caprimulgus Europaus), the spotted fly-catcher (muscicapa grisola), and the sedge-bird (motacilla salicaria). In this and the following month, the dotterel is in season. See our last volume, p. 133.

The charming minstrels of nature, who pour forth such a concord of sweet sounds in this month, are well pourtrayed in 'Kleist's Vernal Season', as translated by Mr. Lloyd'. Although the scenery of this spring is sketched from the north of Germany, it may with little variation pass for that usually observed in Great Britain at this season.

In chorus full, ye feathered warblers, join
My soul to ravish with your notes divine!
Hark! they begin! to the symphonious sound,
The shadowing oak and lofty beech resound.
Soft floats the strain along the silent glade,
And well-pleased Echo lends her willing aid.
The piping bullfinch, and the linnet grey,
Pour from the alder top their varied lay.

See the whole Poem in the New Monthly Magazine, vol. xi.'

N

1

The painted goldfinches delight to sport,
Hopping from shrub to shrub; and oft resort
Where in the hedge the downy thistle blooms;
Light flows their song, and varied as their plumes.
Concealed in shades obscure, in mournful strains,
The siskin of his cruel mate complains.

Perched on the lofty elm, with pow'rful throat,
The deep-toned blackbird tunes his cheerful note.
Far off retired in some sequestered dell,
Where chill despair and pining sorrow dwell,
Where veiled in thicker shade night shuddering fled,
When fair Aurora raised her dewy head,

The little nightingale, whose pride disdains
Th' unworthy contest, pours her rapturous strains.
Oft where beside the oziered pool's dark bed
The mournful willow hangs its drooping head,
When in the wind the waving branches play,
To call her mate she tunes her tender lay.
In thousand various tones, now soft and low,
Mildly she bids the gentle numbers flow.
Now, as his skill some wise musician tries,
In rapid wild transition bids them rise,
Till loud and deep, tho' full of sweetness still,
The silent vale and listening grove they fill.

The insect tribes continue to add to their numbers; among these may be named several kinds of moths and butterflies (papilio atalanta, cardamines, ægeria, lathonia, &c.)

To the BUTTERFLY.

Child of the sun! pursue thy rapturous flight,
Mingling with her thou lov'st in fields of light;
And, where the flowers of paradise unfold,
Quaff fragrant nectar from their cups of gold.
There shall thy wings, rich as an evening sky,
Expand and shut with silent ecstasy!

-Yet wert thou once a worm, a thing that crept
On the bare earth, then wrought a tomb and slept!
And such is man; soon from his cell of clay

To burst a seraph in the blaze of day!

Other insects now observed, are field crickets (gryllus campestris), the chaffer or may-bug (scarabæus melolontha), and the forest-fly (hippobosca equina), which so much annoys horses and cattle. The female wasp (vespa vulgaris) appears at the latter end of the month.