March ii, .1875J 



NA TURE 



369 



METEOROLOGICAL OBSERVATIONS IN THE 

 PYRENEES 



MDURUOF, the French aeronaut, has just com- 

 pleted a series of three ascents executed from 

 Pau, for the purpose of studying the state of the atmo- 

 sphere during the recent cold season. Thrice M. Duruof 

 started with a north wind at the surface of the earth, and 

 thrice he was able to find an upper current blowing from 

 the south. The last time he started at 1.30 p.m., travelled 

 upward until 2.30 r.M., moving southwards, when having 

 reached a higher level he was carried northwards. He 

 landed safely at 4 p.m. in the department of Gers. 



He found in his last trip that the wind was veering 

 regularly with increasing altitude, and was steady at 

 certain levels, so that it was possible to go in any direction 

 by keeping the proper altitude for a sufficient length of 

 time. All his changes of direction were traced on an 

 Ordnance Survey map. His readings and observations 

 will be sent to the Academy of Sciences for further dis- 

 cussion. 



It was observed during the recent cold period that 

 the barometer was low with a northern wind, which is 

 unusual. The three ascents of Duruof may be regarded 

 as affording an explanation of the fact, if we suppose the 

 southern current to have been general at an altitude of 

 4,000 to 9,000 feet above the earth. 



The superior current on the 4th of March was carrying 

 immense quantities of snow at a temperature of 0° C. 

 The snow rapidly melted in its descent, as the air was 

 mild bslow. It is probable that this snow was caused by 

 the influence of the Pyrenean range, which is very cold. 

 I observed at Paris an effect which can be ascribed to 

 similar causes, from hilly parts of our geological basin 

 situated in the south. On that very day the sky was 

 covered in the south and blue in the north, where im- 

 mense plains extend to any distance. 



At all events the southern aerial stream which carried 

 the balloon northwards was very thick. M. Duruof was 

 unable to find its upper surface, although he reached the 

 level of 11,000 feet. 



Other ascents will be made by the same enterprising 

 aeronaut, whose special attention has been so long de- 

 voted to the utilisation of various currents according to 

 altitude. W. de Fonvielle 



SCIENCE AT THE NEW PARIS OPERA* 

 II. 



ALL branches of Physics are represented in the New 

 Opera ; Heat, Light, Optics, Electricity, Acoustics 

 play their different parts. So far as acoustic instruments 

 are concerned, wc may refer to an organ constructed by 

 M. Cavailld-Coll, and formed of eighteen registers, distri- 

 buted over two key-boards, and a complete foot-board. This 

 organ is worked by four pedals, vibrating the air contained 

 in 1,032 pipes, of which some are more than five metres 

 in height, and above '30 metre in diameter. But it is the 

 electric light which has most interest for us. 



After giving a brief account of the invention and history 

 of the voltaic pile, M. Tissandier proceeds to describe the 

 battery connected with the New Opera, which has been 

 organised by M. Duboscq. 



The electric light may be thrown upon the magnificent 

 stage by means of a Bunsen battery of 360 elements, 

 which is established in a room on the ground floor, the 

 length of which is not less than seven metres. M. Duboscq 

 has here arranged six tables of 275 metres long by 75 

 metre broad, which each support a Bunsen battery of sixty 

 elements (Fig. 5). This battery is placed upon the table 

 which is made ol very thick unpolished glass that cannot 

 be injured by the acids. The elements are arranged in 

 four rows of fifteen each. The table is provided under- 



" Continued from p. 351. 



neath with a board which supports a large rectangular 

 basin, in which the plates are placed after they have been 

 used. The jars of the battery, filled with nitric acid, are, 

 after being used, placed in a tub containing the acid and 

 closed with a wooden lid. 



In order to work a battery of such power under favour- 

 able conditions, M. Duboscq has had to make special 

 arrangements for the preparation of the sulphuric acid 

 liquid as well as for the zinc amalgams necessary to put 

 the system of batteries in action. 



C o u r 



Fig. s. — Plan of the Electric Room at the New Opera. 



At the right comer of the electric room is a large reser- 

 voir, of the capacity of about one cubic metre, where water 

 mixed with one-tenth of sulphuric acid can be stored. A 

 spigot permits this liquid to run into a vertical siphon 

 formed of a large tube, into which an areometer is plunged 

 to ascertain its quality, and make sure that the prepara- 

 tion has been made in the proper proportions. The 

 reservoir is furnished at its lower pan v/ith an earthenware 

 pipe which is conducted along the walls of the room, 

 opposite the six battery tables. Beside each table an 

 earthenware spigot enables the operators to run the liquid 

 into earthenware jugs, from which they fill the battery 

 jars with the liquid. 



By an excellent precaution M. Duboscq has obviated 



