1184 



METEOROLOGY. 



[CLAISHER'S BALLOON ASCENTS. 



wbenoo it had arisen* very common occurrence, 

 indeed, at U aeen in the little "black*" that so abun- 

 dantly fall during heavy weather, in large towns, and 

 which result from the aggregation of tho carbon, Arc., 

 in the suioko. Hence, tho inhabitants of such a place 

 would livo in an atmosphere completely stagnant, and 

 daily becoming more impure ; tho culminating effect of 

 which would bo disease and death. Locally, on the 

 small scale, this U constantly occurring in narrow streets, 

 alleys, and crowded dwellings ; and, generally, whenever 

 the air has become still, and unaffected by moving 

 > . 



But the very irregularity in the physical constitution 

 of an atmosphere such as ours, is productive of the 

 most beneficial results. Never at rest in itself which it 

 would be if in its normal condition it is ever susceptible 

 of external influences ; hence the refreshing breezes that 

 course down our streets, or the boisterous March and 

 November winds, wliich, scavenger-like, cleanse our 

 fever-stricken courts and alleys. The very characteristic 

 which seems to prove it an exception to that regularity 

 of law prevalent in nature, is that which forms one of its 

 most valued qualities, making it life-giving in its energy, 

 whilst its stability of position would be synonymous with 

 death. 



Reverting, after this brief digression, to the results 

 obtained by Mr. Ulaisher, we may notice the actinic 

 observations made during the ascent. By Herschel's 

 Kctiuomotcr, the force of the sun's rays was shown, at 

 11 A.M. (at tho Wrottesley Observatory), by 48 divisions 

 in one minute ; and at 5 P.M., by 25 divisions, the sun 

 being then low. At Oh. 8m., during the ascent, the 

 increase was, with a bright sun, 5 divisions in one 

 minute ; at the height of 13,000 feet (at 9h. 29m.), it was 

 7 divisions; at 10,000 feet, the increase was about 1 

 or 8 divisions; at lOh. 7m., or 8,000 feet elevation, it 

 was 20 divisions ; at lOh. 19m., and at a height of a little 

 over 1,000 feet, it was 25 divisions ; and on the ground, 

 at lOh. 45m., the number was 48. With respect to 

 solar radiation, a delicate blackened-bulb thermometer, 

 at heights varying from 13,500 to 1,000 feet, in tho 

 descent, showed a variation not exceeding 4 to 8" 

 beyond that of the shaded thermometers : at tho height 

 of three miles, although the sun shone brightly, the 

 blackened bulb showed an excess of but 2 to 4 ; whilst, on 

 the ground, that became 30. The observations, during 

 previous ascents, had proved that a self-registering 

 blackened-bulb thermometer, in vacuo, with its bulb 

 always in the beams of tho sun, never read BO high as 

 before leaving the earth ; and on being re-set, indicated 

 a reading but little beyond that of the shaded thermo- 

 meters. This result very possibly arose from the great 

 capacity that rarefied air has for heat, which would cause 

 the immediate loss, by radiation, of nearly all tho caloric 

 absorbed by the bulb during its exposure. 



A sky spectrum, with the lines visible from B to G,* 

 waa observed, from 7h. 58m. to 9h. 4m., at heights 

 varying from 3,001) to 13,000 feet ; from 9h. 22m. to 9h. 

 43m., and at heights between 15,000 and 18,000 feet, the 

 spectrum extended from A to H, at which latter point it 

 became extremely dark, whilst tho lines in the violet 

 end were very numerous. Wo have already remarked 

 that the actinic rays wore most activo at high elevations ; 

 and Professor Piazzi Smith, during the British Associa- 

 tion Mooting of 1803, furnished some very interesting 

 focU, which we may conveniently give, as verifying the 

 observations of Mr. Glaisher. He stated that, in 1856, 

 the chief object of astronomical experiments made on the 

 Peak of Tencriffo, which has a height of 12,000 feet, was 

 to ascertain the degree of improvement in definition, 

 obtained whilst using tho telescope at great elevations. 

 It was found the air being so dry and clear that stars, 

 when viewed by powerful instruments, always gave clear 

 an 1 well-defined discs, surrounded with regularly formed 

 rings, even when a high magnifying power was used. 

 He Lad recently magnified some of the photographs taken 

 on Trneriffe, in 1850, at various elevations, and found 

 that their clearness and definition depended on the clova- 



SM ault f. 66. 



tion, and that they remarkably confirmed the results of 

 telescopic observation. Near tho sea-level a photograph 

 could never be taken which would show clearly the 

 detail on the side of a distant hill, however brightly tho 

 rocks or cliffs were illuminated by strong sun-light ; tho 

 microscope only brought out a broad, faint, and nearly 

 uniform tint. On tho other hand, photographs taken at 

 high elevations, exhibited clearly, and well-defined, the 

 most minute detail ; even bushes on a lull-side, distant 

 four-and-a-half miles, were distinctly marked. 



With respect to the amount of ozone, which was 

 observed in the last ascent of Mr. Glaisher, it appeared 

 that none was shown by papers freely distributed about 

 the car ; but ozone powders, made of wheat-starch and 

 iodide of potassium, were slightly tinged when first 

 exposed ; were unchanged at a height of one mile ; 

 but when noticed at 9h. 57m., at a height of about 

 13,500 feet, they indicated an amount of colour eijual to 

 four, when compared with a scale whose maximun 

 is ten. 



We have thus put our readers in possession of the 

 leading facts obtained during the scientific balloon 

 ascents of late years. Whilst they have largely added t 

 our knowledge of meteorological conditions, with ] 

 to the temperature, moisture, quantity of ozone, actinism, 

 (be., of tho atmosphere immediately over the earth, they 

 have entirely dispelled the illusive theory which was long 

 indulged in that tho decrement of temperature was in 

 inverse ratio of the altitude. In a purely theor 

 point of view, such can only bo the case in an atmosphere 

 entirely unaffected by solar radiation and tho convection 

 of heat, and in the absence of purely local disturbing 

 causes. These conditions cannot be present in our at- 

 mosphere, within any elevation approachable by man, 

 above the surface of the earth. Beyond a distance of 

 five or six miles, it is impossible that the observer could 

 exist : indeed, in one of the ascents, this elevation was 

 attained, and nearly proved fatal both to Mr. ( ;lai>ln T and 

 Mr. Coxwell ; the former entirely losing all conscious- 

 ness, -whilst Mr. C. lost the control of muscular action, 

 and was all but a passive observer of the nearly inevit- 

 able destruction of himself and companion. 



There could scarcely have been chosen any situation 

 in Europe in which so many disturbing causes to nor- 

 mal atmospheric conditions are presented. Surrounded 

 by the sea ; of narrow breadth ; situated between the 

 warm Gulf-stream on the west, and the cold polar cur- 

 rents on the north and east our island presents almost 

 a uniqueness of condition in respect to meteoroli 

 phenomena. If circumstances permitted, ascents made 

 in regions less liable to such extraordinary interfering 

 causes, might give some interesting results ; and many 

 parts of continental Europe afford such opportunities. 

 At present, the proper mode of managing tho balloon is 

 but little known, and confined to but a few individuals, 

 who possess sufficient practical skill On frequent occa- 

 sions, the lives of both the aeronauts were in imminent 

 danger ; and it is a matter of great surprise, that so 

 many valuable observations could have been mado under 

 circumstances in which tho majority of persons would 

 have only exerted themselves for their own safety, and 

 regardless of tho interests of science. There can be little 

 doubt that a constant repetition of these experiments will 

 afford a much larger quota of results ; for as, on cadi 

 ascent, tho external conditions of our Ter-ohangeable 

 atmosphere may be expected to vary, n<-w phrii.iinona 

 will present themselves, whilst previously acquired ex- 

 perience will bo prepared to seize on each novelty, and 

 assign to it a proper place in tho departments of meteor- 

 ological science. 



LUMINOUS METEORS, AND THE AURORA Bonp\i,is. 

 During the last few years, considerable attention has 

 been devoted to the study of meteors, the appearance of 

 which has become more frequent, or, perhaps, more no- 

 ticed. Ill 18C2 and 18C3, several largo luminous bodies 

 were seen ; and, amongst them, one was observed, simul- 

 taneously, in the middle and southern districts of Eng- 

 land, and in the north and centre of Franco an i-vi i 

 that it must have travelled at a considerable height 



