1 90 



NA TURE 



{Jan. 4,1872 



dishes. The wind quickly dries the ground, and declines 

 towards night to moderate airs. The influence of these 

 causes is so powerful that I h;ive seen the mercury in 

 the thermomeier placed upon the straw between the 

 dishes descend to 27'', when three feet aljove the ice-pits 

 it was 48". 



So powerful is the coohng effect of radiation on clear 

 nights in tropical climates, that in very favourable morn- 

 ings, during the cold season, drops of dew may sometimes 

 be found congealed in Bengal upon the thatched roofs of 

 houses, and upon the exposed leaves of plants. In the 

 evening the cooling process advances more rapidly than 

 could be supposed by one who has not experienced it 

 himself, and proves the justness of his feelings, by the aid 

 of the thermometer. In the open plain on which the ice is 

 made, 1 have seen the temperature of the air, four feet 

 above the ground, fall from 70'5 to 57 , in the time the sun 

 took to descend the two last degrees before his setting. 



The tropical rains are succeeded by the cold season, when 

 the night is cold, the sky quite clear, and the air becomes a 

 bad conductor of electricity, from the dry northern winds 

 which then prevail. This is proved by the rapidity with 

 which evaporation proceeds, by the dispersion of clouds, 

 and by the more evident proofs which the hygrometer 

 exhibits. During the cold season vegetation proceeds, 

 and electricity continues to be evolved by living bodies, 

 and during their decomposition. 



These remarks will enable us to explain the process by 

 which the ice is prepared in Bengal. 



I St. The large quantity of dry straw and moist dishes 

 rapidly become cold, by their powerfully radiating surfaces, 

 at the same time that the large body of dry straw strongly 

 attracts positive electricity, and the descending currents of 

 air deposit moisture in the dishes of water. Hence, 

 during a cold and clear night, with airs from the N.N.W., 

 the cooling process will advance more rapidly in propor- 

 tion to the non-electric or attractive nature of the body, 

 which, with the radiating power of the surface, regulates 

 the cold and the quantity of dew deposited upon the body. 



2nd. The high and dry situation and free exposure of 

 the ice-fields to the sky, and the aljsence of all causes 

 which could interrupt the inlhience of the large body of 

 non-electrics, and the extensive surface of jiowerful 

 radiating substances, sufficiently accounts for the degree of 

 cold produced in the ice plates ; and 



3rd. The cool, dry north-west airs slowly pass over 

 the ice-beds, absorbing tlie accumidation of moisture 

 and of heat, which is given off by the liquefying of a large 

 quantity of water that would otherwise accumulate over 

 the beds ; and, thus retaining the air clear and dry, allows 

 the full operation of the other causes, particularly radia- 

 tion. T. A. Wise 



NOTES 



' The Academy of Sciences in Paris publishes the following 

 telegrams received from M. Janssen. One dated Ootacamund, 

 l8th December, i'' 6"' p.m., says ; "Great hydrogenous atmo- 

 sphere very rare heyond chromosphere." The other, received 

 on the 19th December by the Mhiistcr of Public Instruction, but 

 uol d.iled, simply says : '\]*xlipse obsei'ved ; import.anl results." — 

 The Royal Academy of Sciences at .\msterdam has received the 

 following telegram from one of its members. Dr. Oudemans, of 

 li.atavia : — " Preliminary results : Corona distinctly seen, pure 

 white rays, dark rifts as far as the moon's limb ; no outline of 

 cliromosphere ; radial polarisation of Corona ; no magnetic dis- 

 turbances ; moving shadows positively observed." 



At the meeting of the French Academy, held on Saturday 

 last, to fill up the four vacant chairs, M. Thiers, M. de Remusat, 

 Minister for Foreign Affairs, and M. Dufaure, Minister of Jus- 

 tice were present and voted. The first election was for a suc- 



cessor to Montalembert, and the Due d'Aumale received 28 

 votes, one blank vote being recorded. For M. \'illemaine's 

 chair there were three candidates, M. Littre, who obtained 1 7 

 votes ; M. Taillandier, 9 ; and M. de Viel Castel, 3. There 

 were six candidates for M. Prevost-Paradol's chair. M. Camille 

 Rousset had 17 votes ;'M. de Viel Castel, 7 ; M. de Mazade, 3 ; 

 M. <le Lomenie, i ; M. Taillandier, i ; and M. Mary-Lafon, o. 

 The choice of a successor to Prosper Merimee was only made 

 after two ballotings. At the first essay M. Edraond About ob- -i 

 tained 13 votes; M. de Lomenie, 13; M. de Viel Ca-.tel, 2; M. 

 de Mazade, i ; and M. Mary-Lafon, o. At the second ballot M. 

 de Lomenie received 15 votes, and M. Edmond Al)Out 14. Pre- 

 vious to tlie election a protest in the form of a lengthy pamphlet 

 was distributed among the Academicians by the Bishop of 

 Orleans, who, while professing the utmost respect for the per- 

 sonal character of M. Littre, declared that now, as in 1863, he 

 opposeii the admission into the Academy of one who in his 

 writings was the defender of Materialism, .\theism, and Social- 

 ism. We learn that in conseqvience of M. Littre's election, 

 Monseigneur Dapanloup has resigned his seat in the Academy. 



SvWe greatly regret to_hear of the death, announced by telegram, 

 from choleraic diarrhoea, of the Venerable John] Henry Pratt, 

 M.A., Archdeacon of Calcutta. He was educated at Caius 

 College, Cambridge, where he took his B.A. degree in 1833, 

 when he was third wrangler, the Masters of Christ's and Sidney 

 Sussex Colleges being also wranglers, with Dr. Boustead, after- 

 wards Bishop of Lichfield. In 1838 he was appointed to a 

 chaplaincy in connection with the East Indian Company, and 

 in 1850 was nominated to the Archdeaconry of Calcutta, which 

 he held up to the time of his death. He was well-known for 

 his rescarehes of the inteiior structure of the earth, and had been 

 a frequent contributor to our columns. 



Dr. Gustav Radde, Directorof the Natural History Museum 

 at Tiflis, has just returned to that town from an interesting journey 

 to the head waters of the Euphrates. Mr. H. E. Dresser has 

 recei\ed a letter from him, dated Tiflis, Dec. 14, from which we 

 translate tlie following extract, viz. : — " Early in August I as- 

 cended, in company with Dr. .Siewers, a young geologist, the 

 Gre.at Ararat, and we reached an altitude of 14,233 feet above the 

 sea level. Our journey extended over three months, and \ve 

 have brought back a splendid botanical collection, many good 

 insects, and geological specimens. Vou will read full particulars 

 erelonginPetermann's'Mittheilungen.' As regards ornithology, 

 I have not, I am sorry to say, time now to write further respect- 

 ing the good materials we gathered together, and am just leaving 

 home for another month. " 



The Professors to the Newcaslle-on-Tyne College of Physical 

 Science have determined to institute evening classes, to com- 

 mence immediately after the winter vacation, for the purpose of 

 giving instruction in their respective subjects to persons who are 

 I unable to attend their day classes. The Piofessors wish it to 

 be understood that the instruction given in these classes will be 

 such as to require a certain amount of real study on the part of 

 those who attend them. 



The Curator of the Clifton College Museum, Mr. Barrington 

 Ward, has issued a circular asking for donations, to which we 

 are glad to call attention. The following extract will show tlie 

 very wise limitation placed on the .acceptance of specimens: — 

 " It has been decided, with the approval of the Head Master, 

 that the museum shall be essentially a British one, and shall 

 illustrate the natural history and antiquities of our land by good 

 specimens, systematically arranged, under the departments of 

 zoology, botany, geology, mineralogy, and archaeology. In 

 addition to this there will be a collection of rare and curious 

 objects, derived from all sources, which may be considered use- 

 ful for the purposes of scientific teaching, and a large typical 



