« AnteriorContinuar »
other astronomical calculations, which may be briefly enumerated here, and some of which will be illustrated in the subsequent pages. From what is explained above, it is obvious that it is necessary in finding the latitude of a place from an observation of the meridian altitude of the Sun; and it is also equally requisite in finding the latitude from two observed altitudes with the interval of time between them. It is likewise used in computing the Sun's azimuth from his altitude and the latitude of the place, in order to find the variation of the mariner's compass; as well as in computing the Sun's altitude from the latitude of the place and the horary angle. The Sun's declination is also necessary to be used in calculating the apparent time from an observed altitude of the Sun at a distance from the meridian, the latitude of the place of observation being known; or to compute the time of the Sun's rising and setting. For any of these purposes, the declination taken from the table should be reduced to that corresponding to the required time, by the preceding proportion.
The Naturalist's Diary
For JANUARY 1820.
The earth with fresh flowers was still covered o'er;
They bloomed, though the season of youth was no more.
Its tenants no end to their happiness knew';
And the bird of the spring lingered all the year thro'.
Though often it lours in our northern skies,
As of old it appeared to the Bethlemites' eyes. Such is the poetical description of the winter of 1818-19, as it was experienced in England. The singularly mild temperature of this winter, and the
want of frost and snow, was not confined to our own island; it was equally observed in almost all parts of the European Continent. In Sweden, and most parts of Russia, they had, instead of the usual degree of cold, a temperature of several degrees above the freezing point. This was the case even in Lapland, to the north of Tornea, where, instead of the usual cold of 200 of Reaumur, they had 69 of warmth. This want of frost and snow proved a serious inconvenience in these northern regions, by preventing the conveyance of the iron ore from the mines in Sweden to the smelting houses; and in Russia, the carriage of goods from the interior to the seaports for exportation, which is regularly done in the
winter, when the hard frozen ground, covered with snow many feet deep, affords a solid, even, and commodious road.
From the Meteorological Journal kept at the Botanic Garden of Geneva, the same phenomenon, of want of snow, appears to have occurred on the Alps. In the three months of October, November, and December, there was only once so much as a white frost. In the whole course of November, says the Journal, 'the snow has not lain a single day on the mountains that surround our lake. This is a phenomenon of which the oldest inhabitants can remember no previous instance. The wheat is remarkably beautiful; the cattle are still in pasture as in the month of September. The same Journal, for December, says, the continued fineness of the temperature, during this month, is without parallel in our country. Mount Jura, which is generally covered with snow in November, is still almost totally free from it to-day, the 31st of December. There is none at all on the summit of La Dole, and very little on the summits near fort L'Ecluse. In consequence of the dryness of the temperature all the year, the springs are very low, and we begin to be uneasy for next year, seeing that the mountains have no snow at all on them.'
Although, of late years, comparatively without snow, the month of January is not without its storms of wind and rain.
From the pallid sky the sun descends,
That, solemn sounding, hids the world prepare.
' Epitaph on a ROBIN REDBREAST.
gate, and fly to the warm stubble for shelter; and the nut-hatch sitta europea) is heard. The shell-less snail or slug [imax) makes its appearance, and commences its depredations on garden plants and green wheat. The missel thrush (turdus viscivorus) begins its song. This bird sings between the flying showers, and continues its note till the beginning of August. His food consists of berries and insects, but principally the former. The fruit of the hawthorn, elder, spindle-tree, sloe, and holly, occasionally supply him; but the misseltoe, from whence he takes his name of viscivorus, is his favourite food. As bird-lime is often made of its glutinous berries, and this thrush is supposed to increase the misseltoe by depositing the seeds he has swallowed on other trees, he is said, in a Latin proverb, to propagate the means of his own destruction.
Oh, herald of the Spring! while yet
No more in lone and leafless groves,
-Gone to the world where birds are blest!
ROGERS, C. SMITH.
Still may thy pest, with lichen lined,
Thy song of Hope and Fortitude! The hedge-sparrow (sylvia modularis) and the thrush (turdus musicus) now begin to sing. The wren, also, pipes her perennial lay,' even among the flakes of snow. The titmouse (parus) pulls straw out of the thatch, in search of insects; linnets (fringilla linota) congregate; and rooks (corvus frugilegus) resort to their nest trees. Pullets begin to lay; young lambs are dropped now.
The house sparrow (fringilla domestica) chirps; the bat (vespertilio) appears ; spiders shoot out their webs; and the blackbird (turdus merula) whistles. The fieldfares, red-wings, skylarks, and titlarks, resort to watered meadows for food, and are, in part, supported by the gnats which are on the snow, near the water. The tops of tender turnips and ivy-berries afford food for the graminivorous birds, as the ringdove, &c. Earth-worms lie out on the ground, and the shell-snail (helix nemoralis) appears. See some lines to the snail in T. T. for 1818, p. 23.
Of the uses of snow, particularly its important services to vegetation, we have spoken at large in our former volumes. The late expedition to the Arctic Regions has made us acquainted with a variety of this elegant phenomenon of nature, in the shape of crimson snow; its appearance is thus described in Capt. Ross's Voyage :
* August 17. We discovered that the snow on the face of the cliffs presented an appearance both novel and interesting, being apparently stained, or covered by some substance, which gave it a deep crimson colour. At2 P.M. it fell nearly calm, and I sent a boat with Mr. Ross, midshipman, and Mr. Beverley,