CLOVER. 



Ml 



Thus, it appears that in the month of September, for instance, for 

 MTen times that the clouds were between 200 and 300 yards high, there 

 were 88 times in which they were between 500 and 600 yards high, tc. 

 The supposition of the height of the clouds depending on the barometer, 

 was in no degree countenanced, and though in heavy and continued 

 rains the clouds were mostly below the summit, yet it frequently rained 

 when they were above it. These observations, however, are chiefly 

 valuable in relation to the local phenomena. (See J. F. Miller on the 

 Meteorology of the Lake District, in ' Phil. Trans.,' 1848, p. 87.) Of 

 much greater importance are those of the late Mr. John Welsh, F.R.S., 

 in four balloon ascents, made in 1852, under the direction of the Kew 

 Observatory committee of the British Association for the Advancement 

 of Science, and published in ' Phil. Trans.,' 1853. The ascents were 

 all made from Vauxhall Gardens, on the south bank of the river 

 Thames, in the south-west district of London. 



At the first ascent, on August 17th, 1852, clouds covered about 

 three-fourths of the sky, the lowest stratum being a few detached 

 mnnsrn of loose cumulus ; a dense mass of cirro-stratus (or stratus) 

 being above, with perhaps occasional patches of cumulus intermediate. 

 The altitude of the lowest clouds, which extended only over a small 

 area, was estimated during the ascent at about 2500 feet, or 500 feet 

 less than that of Skiddaw. Between this and about 13,000 feet, the 

 air seemed free of clouds ; after this, there seemed to be occasional 

 mnnnrn of loose cumulus at no great distance. When at the greatest 

 elevation, 19,510 feet, or about three miles and three-quarters, there 

 was, at apparently a short distance above the balloon, a thick mass 

 of cloud, probably the cirro-stratus which had been seen from 

 the earth. At this elevation the temperature was 9'5, or 22'5 

 below freezing ; and at about this time, though while still rising, a 

 few small star-shaped crystals of snow fell, a fact coincident with 

 what has been remarked in a former part of this article, of the 

 probably frozen condition of cirrus. At the second ascent, on the 

 26th of August, the sky was to a small extent obscured by detached 

 missrai of cumulus, but the sun shone brightly throughout the ascent 

 The only clouds passed were at the estimated height of 3000 feet; 

 above this no clouds were met with, while the ascent was made to 

 19,100 feet, the sky being exceedingly clear, and of a very deep blue 

 colour. The third ascent was made on October 21st, on the morning of 

 which a fog which had existed on the previous night slowly disappeared, 

 leaving the air in a very calm state and with some haze. A dense 

 mass of cloud, probably stratus, covered the sky; one or two slight 

 bowers falling about 10 A.M. Between the heights of 1000 and 2800 

 feet various detached and irregular masses of loose " scud " were 

 encountered, but the balloon had not completely entered the dense 

 man of cloud till the height of nearly 3000 feet. At a height of 3700 

 feet the upper surface of the cloud was reached, and the sun was Been 

 shining through thin cirrous clouds at a great height. The height 

 of the upper surface of the cloud was again observed during the 

 descent to be 8450 feet. When the balloon was close to the clouds, it 

 was remarked that the general level of the surface was very uniform, 

 presenting however a hillocky appearance ; the irregularities being 

 mull, apparently not exceeding a very few feet Shortly after clearing 

 the clouds, a shadow of the balloon was seen on the surface, fringed 

 with a glory ; with thin nhadow as a centre, there was also observed a 

 circle of whitish light, the outer edge of it slightly tinged with yellow ; 

 its diameter being estimated at 80. About this time there was 

 noticed, stretching for a considerable length in a serpentine course 

 over the surface of the cloud, a well-defined belt, having the appear- 

 ance of a broad road, both sides being Htrikingly distinct The thin 

 cirrous clouds already mentioned seem not to have been passed, the 

 lUsomt being made from the elevation of 12,640 feet, at which the 



temperature was 207'. 

 The reader 



reader will not fail to connect the thin cirrous clouds seen at a 

 great height, through which the sun wan nhining, with the glory and the 

 circle of light surrounding the shadow, and remark in reference to the 



frown state of such clouds both the fact that they were above 1 

 feet, and the temperature observed. Perhaps the serpentine belt may 

 have been the horizontal summit or upper plane of a comparatively 

 narrow current of air with vertical sides, which had deposited ita own 

 mass of cloud, in the form of a waved wall. 



The fourth and last ascent took place on the 10th of November, 

 when the surface wind and the lower current of "scud" were moving 

 very slowly; the upper clouds were only occasionally visible. 

 height of 500 feet the first cloud, thin scud, was entered, the upprr 

 surface being 1970 feet high. A space of 2000 feet was clear of clouds, 

 and at 4000 feet the second stratum of clouds was reached, its upper 

 surface being found to be 4900 feet high. After this no clouds were 

 met with, the sun shining through thin cirrous clouds, which 

 have been at a very great height. The greatest elevation attained was 

 22,930 feet, and the lowest temperature observed, at 560 feet lower, 

 was 10-5 below zero. So that the height of the cima was above 

 23,000 feet, or about four miles and three-eighths, at which it imi.-t 

 necessarily have been frozen, to have a visible existence in clear 

 sunshine ; and the same inference may in fact be drawn with respect 

 to some of the preceding instances at much lower altitudes. 



The nautical term </, denoting, apparently, broken fragnu i 

 cloud, is frequently employed by meteorologists at the present time, as 

 jy Mr. Welsh above, and in the Greenwich observations ; but we must 

 confess our ignorance to what modification and in what state it is 

 intended to apply, or whether it is regarded as equivalent to an 

 additional modification : an ignorance in which wo know Mr. Howard 

 a participate. Its undefined use seems to indicate insufficient atten- 

 tion to the structure of the clouds. 



Of the elevation and distribution of the clouds at Teneriffe, v. 

 some definite information iu Professor C. Piazzi Smyth's report 

 ; already cited) of the astronomical experiment of 1856 made on the 

 Peak (or in ' PhiL Trans.,' 1858), pp. 481, 527. Observed both from 

 the upper station of Alta Vista at the height of 10,702 feet above 

 the sea, and the lower one of Guajara at that of 8,903 feet thai: 

 and mountain-cloud existed below and appeared daily, dense, closely 

 packed together, and rolling upon each other they showed no tendency 

 bo rise higher than 4500 feet, or rather more than seven-eighths of a 

 mile. With this depression of the mountain-cloud, including cumulus, 

 cumulo-stratus, and nimbus, below him, Professor Smyth had, he found , 

 but the thinner forms of cloud, cirrus, cirro-cumulus, and some cirro- 

 stratus, ever at any time floating above him, or interfering with tin- 

 view of the heavens ; and these only appeared about once in five day* 

 in any considerable quantity. The lowest strata of cloud, he observed, 

 were 2300 feet, or less than half a mile, above the sea; of the elevation 

 of the upper clouds he had no means of accurately judging, but he 

 suspected that it could not have been less than 15,000 feet, or nearly 

 three miles. Sometimes there was cloud on the summit of the Peak, 

 which gives a height of 12,000 feet, about two miles and a-q 

 Professor Smyth also observed that the stratum of the mountain-cloud 

 of Teneriffe did not occur in the space between the two winds whirh 

 were found blowing at the top and bottom of the mountain, i 

 lively, the S.W. wind above and the N.E. trade-wind below [CALM], 

 but in or below the middle of the N.E. current of air, which extends iu 

 height from the very sea itself to about 9000 feet The mountain- 

 cloud is limited in horizontal extent to a few miles, but even the sea- 

 cloud, the true N.E. cloud, which was far more extensive, stretching as 

 far as the eye could observe, when viewed from many thousain 

 above, and extending, in fact, several hundred miles from the island, 

 only reached to between 4000 and 5000 feet of elevation, or to hall the 

 height or depth of the N.E. wind, in the midst of which, like the 

 mountain-cloud, it was thus included. It seems probable, therefore, 

 that in all climates, the rainlosn tracts excepted, a considerable stratum 

 of cloud commonly exists over the land, the inferior surface of which 

 is at a height varying from somewhat less to rather more than half a 

 mile, or from 2600 to 3000 feet, whatever of cloud there may or may 

 not exist above or ).,l.\v that altitude. [CLIMATE; DEW; EVAPORA- 

 TION ; HAIL ; HALO ; HTUROHETUY ; LIOUTIJINO ; METEOROLOGY ; 

 KMN; SNOW; SKY; VAPOUR.] 



CLOVER, a name given to different species of Trifolium. Dutch 

 clover is T. repem; purple clover is T. ]>rataae ; cow-grass, or | 

 nial clover i T. pratcHtc pertim- : Al-ikc clover is T. hybrid um ; T. 

 ...-'i. a m is aUo called cow-grass; scarlet clover T. ; hop 



tiet'oil in T. procumbent. 



r was introduced into the agriculture of Great Britain 

 the 16th century, from the Low Countries, where it had been long 

 cultivated OB green food for cattle in situations where natural pastures 

 were scarce. It was the first step towards the improvement of tin- "M 

 triennial system. Its abundant produce, it destruction of I 

 weeds, which it smothers by its broad foliage, and especially the 

 beauty of the wheat sown after it, soon recommended it as an indis- 

 pensable part of an improved rotation of crops. It is not too much to 

 say, that under certain kinds of management, the profit of any farm 

 may be considered as proportionate to the quantity of clover hi, -h IK 

 produced upon it on an average of years. There are various kind.-, of 

 clover, which all go under the botanical name of t, -.in tin- 



three leases which grow together, or rather the form of the leaf, which 

 has three heart-shaped part*. They are annual, biennial, or perennial 

 plants. The annual clovers, with the exception of the trifolium inc:ir- 

 natum (Trifa incarnat or farouche), introduced from the south of 



