5o8 



NATURE 



[Oct. 5, 1876 



THE RADIOMETER IN A BALLOON 



THE Count Elemer Bathyani made a private ascent in 

 the Tricolore balloon on Monday, August 28, with 

 Duruof as an aeronaut. The balloon started from La 

 Villette Gasworks at 11.50 in the morning, and descended 

 at Chevru, near Coulomiers, about forty miles from Paris, 

 at 2 o'clock, after having run little short of a hundred 

 miles. The aerial craft had been overtaken by a series of 

 winds in different directions. The culmination of the 

 ascent was 2,500 metres. 



The objects of Count Bathyani were to rotate the radio- 

 meter at different altitudes, so as to illustrate the augmen- 

 tation of the luminosity of the sun, and to condense the 

 vapour of clouds with an ether evaporator, in order to col- 

 lect molecukc suspended in the air, and ascertain whether 

 vapour was mixed with a certain quantity of ammoniac, 

 nitrous or nitric compounds, or ozone. The last opera- 

 tion could not be executed, because the balloon did 

 not meet a true cloud, having passed in the superior rone 

 through lacunas, between the several cumuli. But the 

 radiometer experiments were successful, and we are 

 enabled to give a correct table of the results obtained. 

 The radiometer was blue-red, constructed by Gaiffe. 



In the Shade. — On the ground (at La Villette), 35 revo- 

 lutions per minute, with a pressure of 750 mm., sky half 

 covered by disconnected cumuli, temperature, 26° C, at an 

 altitude of 1,750 meters. 



In the 7"r/V(5'/t»r<r floating between cumuli at a distance of 

 1,500 metres from the earth, sixty-four rotations per 

 minute — temperature, 15°. 



In the Sun, — Time iih. 50m. Temperature 18°, alti- 

 tude 700 metres, sun shining \ hrough a layer of clouds fifty- 

 four rotations per minute. Time ih. lom. Altitude 2,300 

 metres, temperature 13°. Sun .shining; it is impossible 

 to measure the number of revolutions, which are as great, 

 if not greater, than with an ordinary white-black radio- 

 meter exposed to a radiant sun at the surface of the earth. 



M. Gaitfe is constructing another differential radiometer 

 to totate under similar circumstances. One of the faces 

 is to be white, and the other white with a black spot in 

 the centre. The evaporator was working with ordinary 

 vinic ether, but with methylic the condensation will be a 

 great deal more powerful. The water in suspension will 

 be precipitated under the form of ice ; the refrigeration 

 of condenser being then 20° C. below zero, all the dust 

 floating in the air in the vicinity of condenser will be de- 

 posited with the ice. The ice is to be collected and ulti- 

 mately analysed micrographically as well as chemically. 



The difficulty is to prepare a vessel for holding the 

 methylic ether, as the pressure is enormous even at ordi- 

 nary temperature. But I was told at Auteuil frigorific 

 works it can be obtained and filled ready for use very 

 eas'ly at a comparatively small expense. 



W. DE FONVIELLE 



THE RECENT TORNADO 

 T T is evident from a correspondence in the Times of 

 ■*■ Friday, Saturday, and Monday last that a tornado of 

 almost unexampled intensity and destructiveness swept 

 over the Isle of Wight and Hampshire on the morning of 

 Thursday, September 28. The storm, which appears to 

 have come from a southerly direction, struck West 

 Cowes about seven in the morning, thence crossed the 

 Solent in a north- easterly direction, and, strikin;^ the 

 opposite coast, near the entrance of Southampton Water, 

 passed up Hampshire between Titchfield and Portsmouth 

 at least as far as Meonstoke, which is about sixteen miles 

 to the north-east of Cowes. 



Its appearance on approaching is described as that of 

 an immense black cloud sweeping along the ground and 

 giving out a low moaning sound which it was awful to 

 hear. A gentleman in a small yacht, which fortunately 

 was out of the course of the tornado, suddenly heard 



sounds very much resembling the noise caused by 

 the escape of steam when at its highest pressure, 

 and at the same tim^ the whole sky became clouded 

 with articles of all forms and sizes which were carried 

 through the air to a heis^ht of about 300 feet and 

 parallel with the shore. The Globe hotel was blown 

 down, and several houses lost their roofs, fronts, or 

 chimneys ; a p'er belonging to Dr. Kernock was wholly 

 demolished, and many of the watermen's boats were sunk, 

 being filled with bricks which had been blown through 

 the air. It is stated that some bricks fell on board Lord 

 Wilton's steam yacht, the Palatine, which was moored half 

 a mile from the shore. At Cowes alone the damage done, the 

 work of only one short minute or two is estimated at from 

 10,000/. to 12,000/. The destructive character of the 

 tornado was maintained in its course through Hampshire, 

 where turnips and other crops were literally dragged out 

 of the ground, fine oak trees uprooted, farms and home- 

 steads damaged, a barn being bodily lifted up, and in- 

 stantly converted into a heap of ruins, and life lost. It 

 made a clean sweep through a thick copse, clearing a 

 path for itself 100 feet in width, along which the trees and 

 underwood were all uprooted, as if men had grubbed up 

 everything. In some cases it is said that the corners of 

 ricks and cottages were cut off as if with a kni'e, and that 

 iron pig-troughs were carried a distance of 300 to 400 

 yards, and gates lifted from their hinges and thrown into 

 the adjacent fields. 



Since the mode and suddenness of its approach, its 

 brief continuance, and its terrible destructiveness, all 

 show that in investigating this storm, it is a true tornado 

 we are dealing with, we hope that, whilst the occurrences 

 are fresh in the minds of those who witnessed them, some 

 one will take the trouble to make a careful collection of 

 the facts. As yet, little of the meteorology of this tempest 

 is before us ; what is required for its investigation is to 

 know along different points of its track the time it began 

 and ended, the changes in the direction of the wind, tem- 

 perature, and state of the sky, and the aqueous precipita- 

 tion accompanying it ; the damage done, the objects 

 whirled aloft, and the direction and course taken by them 

 in their flight through the air. A careful investigation of 

 the facts of this tornado would form a valuable contribu- 

 tion to meteorology at the present time, inasmuch as 

 it would probably enable us to say whether tornadoes and 

 other whirlwinds are to be regarded as typical, as is 

 sometimes alleged of the cyclone of tropical regions and 

 of the ordinary storms which sweep over these island?. 



The services of a sufficient staff of observers are more 

 urgently required to record non-instrumental observations 

 of wind, rain, hail, cloud, &c., from which the broad 

 features of wind-storms, hail-storms, and thunder-storms 

 could be adequately described, and some knowledge 

 arrived at as to the way in which the rainfall is propa- 

 gated from parish to parish. If such organisations were 

 set on foot over different portions of the British Isles, we 

 should soon be in a position to attack several of the more 

 important practical problems of meteorology, and to issue 

 weather-warnings in the interests of agriculture and hor- 

 ticulture as began to be issued in France some months 

 ago. 



Storms seem to have been wandering widely recently. 

 Ten days before the tornado above referred to. a storm of 

 unusual violence visited the American coast, and the 

 Paris Temps received on Saturday evening a telegram 

 from the Puy-de-D6me Observatory stating that a terrific 

 hurricane had been blowing since the morning. It was 

 impossible for the observers to walk outside the house 

 without being blown down. The velocity of wind could 

 not be registered by anemometer. The sky was clear, 

 but clouds were covering the surface of the earth and 

 clinging to the different mountains. On the following 

 night and day the weather was boisterous and rainy at 

 Paris. 



