NA TURE 



\_Nov. 29 1883. 



for a supply of the ln.-ans hoiu Jai>;.ij, mIucIiJic pru, oses to dis- 

 tribute extensively for trial. Muu'h consideration has alio been 

 given to the utilisation of the various fibrous plants. In the 

 Lloyd Botanic Garden, Darjeeling, much damage continued to 

 be done by the cockchafer grubs until pretty nearly every plant 

 in the garden was killed. " The wh ile of the grass in the 

 garden and all herbaceous plants rapidly succumbed to its 

 ravages, as did many of the flowering shrubs, only the deeper 

 rooting shrubs and trees being spared. Even the plants in tlie 

 conservatories did not altogether escape ; eggs of the insect 

 having got in considerable numbers into the soil of the pots.'' 

 In response to vigorous efforts to exterminate this plague aliout 

 six millions of the grubs were collected and destroyed by the 

 garden labourer.-;, so that at the time of writing the Report it v\as 

 showing .signs of disappearing. In Mr. Duthie's Report it is 

 satisfactory to find that economic plants, as at Calcutta, are 

 largely cared for, and that the cultivation of medicinal plant; 

 and the preparation of drugs from them is being proceeded with. 

 Amongst these may be mentioned Alexandrian senna (Cassia 

 acutifolia), henbane {Hvoscyamus ni^er), belladonna {Alropa 

 belladonna), &c. Additions are also being constantly made lo 

 the museum. 



Part V J. of the "Herefordshire Pom>na"has been issued, 

 and Part vii. and last will be published in the autumn of next 

 year, after the Congress and Exhibition of the Pomological 

 Society of France, to be held at Rouen in October. 



In the Japan Mail of August 23 and September 24, Mr. E. 

 Knipping describes ihe course of two storms which occurred, one 

 on August 17 to 20, and the other September 11 to 14. These 

 descriptions show how very . ompletely the Japan meteorological 

 service is organised, and that good work is being done in the 

 Far East in collecting data for scientific meteoroloj^y. 



Messrs. Macmillan and Co. have published as one of their 

 "NATtjRE Series" volumes, Drs. Gladstone and Tribe's "Che- 

 mistry of the Secondary Batteries of Plante and Faure." "About 

 Photography and Photographers" is the title of an interesting 

 gossipy little volume by Mr. H. Baden Pritchard, published by 

 Messrs. Piper and Carter. 



Miss J- M. Hayward wishes to stale with reference to Mr. 

 Denuing's letter (p. 56) that she did give the hour (10.30) at which 

 her letter was written, with the date, at the end. She adds that 

 a clock struck ten shortly before she saw the meteor ; but she 

 thinks the clock was probably slow, as it generally is. She has 

 no doubt it was the same meteor as that seen at Bath, Bristol, 

 and Chelmsford about the same lime. 



The additions to the Zoological Society's Gardens during the 

 pa.st week include two Bonnet Monkeys (Macacus sinicus) from 

 India, presented respectively by Mr. II. G. Rose and Miss 

 Morant ; a Common Fox {Canis vnlpes), British, presented 

 by Mr. H. Vaughan ; two Bullfinches (Pyrrhula ewopita) 

 European, presented by Mr. Archibald Aitchison ; four Moorish 

 Toads (Btifo maurilaniciis] from Tunis, presented by Mr. 

 Frederick Bridges ; twelve Ruffe, or Pope (Acerina cernua) from 

 British waters, presented by Mr. T. E. Gunn ; two Michic's 

 Tufted Deer (Elaphodus michianns (5 9 ), a Chinese Water Deer 

 {Hydropotes inetinis), two Elliot's Pheasants {Phasianus el/ioli) 

 from China, deposited ; six Coal Titmice (Parus aley), British, 

 purchased ; a Spotted Ichneumon (Herpestes nepalensis] from 

 Nepal, five Blue-crowned Hanging Parrakeets (Lorictihis gj/- 

 giihis) from Malacca, received in exchange. 



OUR ASTRONOMICAL COLUMN 

 Pons' Comet.— Mr. S. C. Chandler has communicated to 

 the Astronoinische Nadirichttin his own experiences at the 

 Observatory of Harvard College with reference to the remark- 



able increase in the brightness of this comet on September 22, 

 which has been already mentioned in Nature (vol. xxviii. p. 

 624). He observed with an aperture of 6j inches. On 

 September 21, between 8h. 55m. and llh. M.T. he found 

 the comet very faint and diffuse ; the central condensation or 

 nucleus about equal to a star of 1 1 m. On .September 22, about 

 7h. M.T. he was astonished to find exactly in its place a 

 bright, clearly-defined 8 or 84 mag. star without sensible trace 

 of nebulosity, except witli a power of only 50, giving a field 

 of \\ degrees, and even with that not noticeable except with 

 attention. It was so distinctly .stellar an object that .an expe- 

 rienced observer might hive failed to distinguish it from stars 

 of similar brightness in tlie neighbourhood. On September 23, 

 at 7h. 30m., he found the physical appearance again greatly 

 changed. The nucleus seemed spread out into a confused 

 bright disk about a half minute (arc) in diameter, outside of 

 which was a nebulous envelope much brighter than on the 

 preceding night, and about one minute and a half in diameter. 

 The comet was judged to be a half magnitude brighter than on 

 September 22. On September 25 it appeared spread out into 

 a confused disk two minutes in diameter, a faint nucleus or 

 concentration of light not brighter than 11 m. .So rapid an 

 increase and diminution of light is a very unusual phenomenon; 

 Mr. Chandler thinks that phases of this kind may be charac- 

 teristic of the comet's mode of light development, as the same 

 variation was repeated on a .smaller seal : on October 15, when a 

 nucleus of about 9'3 m. appeared, which gradually dis.sipated 

 on the following evenings, through expan-ion into the general 

 nebulosity. Toe comet's distance from the sun when Mr. 

 Chandler remarked the great increase of brightness was 2*i8, 

 Ihe earth's mean distance being taken as unity, not the least 

 surprising condition in the case. 



In the same number oi i\i& Astronotnische A'ac/iricktenVtof. 

 Schiaparelli gives some account of his observations on the 

 physical appearance of the comet at Milan, which are of much 

 interest in connection with those of Mr. Chandler. On 

 September 22 he found the comet about 3' in diameter, faint and 

 diffuse, the nucleus about 13m., but the sky was not perfectly 

 clear ; the observations for po.sition were made at Sh. 30m. M.T. 

 On September 23, about 8h. 13m., the comet had increased in 

 brightness since the previous evening in an extraordinary manner ; 

 it noiv appeared as a star of 8 m., with a very faint surrounding 

 nebulosity of from i' to li' diameter. The central part was not 

 exactly a luminous point, but had a sensible diameter and in- 

 distinct outlme. On the 25th it was still bright, but the nucleus 

 of the 23rd had spread out so as to form a circular nebulosity 3' 

 in diameter, without notable central condensation. 



Comparing the Milan and Harvard observations, it would 

 appear that the rapid increase in the light of the comet took 

 place between September 22, at 7h. 45m. and lih. 45m. Green- 

 wich mean time ; it remains to be seen how observations else- 

 where will accord with this inference. Mr. Chandler suspected, 

 from a comparison of his own notes with those made by the; 

 observers at Kiel and Vienna, that the increase would be found 

 to have taken place between the European and American 

 observations on September 22. 



M. Bigourdan, of Paris, says on November 19, " The comet is 

 a nebulosity of from sixth to seventh magnitude, with nucleus : 

 the brightest part of the coma, that which borders on (he 

 nucleus, is not .symmetrical about it; it is less extended in' the 

 angle 110° — 140°, and is brightest in the angle 280° — 290"." 

 Taking the comet's theoretical intensity of light on November 

 19 as unity, the intensity on Plecember 31 will be 9'5, and on 

 January 14 (when it is at its maximum), 130. In the absence 

 of moonlight the comet must be, for some time, a naked eye 

 oliject. 



THE GENERAL THEORY OF THERMO- 

 DYNAMICS 



■nTHE first of the six lectures on "Heat in its Mechanical 

 Applications" at the Institution of Civil Engineers vas 

 delivered on November 15 by Prof Osborne Reynolds, M.A., 

 F.R.S., the subject being as given in the title. The following 

 is an abstract of the lecture : — 



Thermodynamics, Prof. Reynolds said, was a very difficult 

 subject. The reasoning involved was such as could only be 

 expressed in mathematical language ; but this alone would not 

 prevent the leading facts and features of the subject being expressed 



