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NATURE 



[December 5, 1895 



The Times of Ceylon learns that it is in contemplation to 

 introduce the electric light into the Sivan Hindu Temple at 

 Kochicadde, on the main road to Mutwal, Ceylon. The 

 premises of this Hindu place of worship are at present lighted 

 by gas, and the trustees propose to substitute the electric light 

 for gas ; but whether they will introduce it into the interior, of 

 the building, is a matter which is now under their consideration. 

 It is said that, if the Sivan Hindu Temple introduce the innova- 

 tion, the trustees of equally wealthy temples are sure to follow 

 the example set by their brethren. 



In reference to his letter on the "Jelly-fish of Lake Urumiah " 

 (Nature, 1892, p. 294), Mr. Sclater informs us that he has 

 lately received a letter from Mr. F, F. Irving, of the English 

 Mission at Urmi, in Persia, stating that Mr. Irving has lately 

 visited the lake, and has found, as has been described by Mr. 

 Curzon, numerous specimens of the supposed jelly-fish in its 

 waters. Mr. Irving says that it resembles a tiny shrimp when 

 swimming, but that as soon as it is brought out it succumbs into 

 a sort of gelatine mass without shape. Measures are being taken 

 to secure the transmission home of specimens of this interesting 

 organism. 



An instance of concerted harmony and measured time-keeping 

 on the part of certain insects, described by Dr. G. M. Gould, of 

 North Carolina, in a recent number of Science, has drawn several 

 letters from entomologists on the subject. Probably most people 

 would hardly recognise music in the stridulous noise made by 

 members of the group Crytophyllus, or " Katydids," and would 

 express surprise at the suggestion that there is any rhythm or 

 unison in the sound. Dr. Gould, however, states that there is 

 no doubt whatever that katydids keep time in their stridulations. 

 So soon as the sun has set in North Carolina an orchestra of 

 katydids begins to tune up. After a few preliminary raspings, 

 the members of the orchestra begin to make their noises to- 

 gether ; another orchestra at once answers them, and so they 

 go on swing-swong, one set answering the other the whole night 

 long. Mr. A. P. Bostwick adds his testimony to that of Dr. 

 Gould as to the antiphonal rhythm of two orchestras of katydids. 

 He has remarked that the antiphony is often very regular for 

 several minutes, sometimes stopping short, and again becoming 

 broken into irregular individual stridulation at the end. The 

 exact unison of movement can hardly be purely mechanical, for 

 the katydids often start their noises all at once. A difference of 

 pitch between the notes of two orchestras was suspected by Dr. 

 Gould ; but Mr. Scudder, who has given much attention to the 

 sounds made by locustarians, thinks this may have been only 

 apparent, and due to difference in distance from the observer. 



That real images of objects are formed upon the human 

 retina seems to be supported by a series of experiments 

 carried out by Mr. W. Ingles Rogers, and described by 

 him in the Amateur Photographer for November 22. Mr. 

 Rogers took a shilling and looked at it intently in ordinary 

 daylight for a furtl minule, with the idea of fixing the image of 

 it distinctly upon the retina. He then drew a yellow screen over 

 the window of the room in which he sat, so as to exclude all 

 actinic light, and, placing a photographic plate in a certain 

 position, fixed his eyes upon the centre of the plate, at the same 

 time allowing nothing but the image of the shilling to occupy 

 his mind. He remained looking at the plate for forty-three 

 minutes, and afterwards developed it, with the result that 

 an outline of the coin was clearly shown upon it. The 

 " psychogram," as the resulting picture is called, was sufficient 

 to show that better results might confidently be expected. 

 Accordingly, Mr. Rogers continued his experiments, and, in 

 order that there should be no doubt about the bond-fide nature of 

 the result, he produced a psychogram in the presence of three 

 trustworthy witnesses, whose testimonies as to the genuineness 

 NO. 1362, VOL. 53] 



of the photographs accompany Mr. Rogers's communication. 

 On this occasion a postage-stamp was used instead of the coin. 

 The stamp was looked at in a strong light for one minute. It 

 was then removed, a plate was put in its place, and the plate was 

 looked at for twenty minutes. The resulting psychogram is 

 reproduced in our contemporary, and although there is aa ^^^ 

 absence of detail, sufficient is seen to prove beyond doubt that a 

 picture of an object, impressed upon the retina, can send out 

 vibrations which will result in the production of an image upon 

 a sensitive plate. The result is of such great interest not only to- 

 photographers, but to students of physiological optics, that we 

 hope the experiments will be continued. 



At a recent meeting of the Paris Academy of Sciences, 

 M. Mascart presented an interesting note on the rainfall 

 at Athens, by M. D. Eginitis, based on observations made at 

 the Observatory during 1878-94. The average yearly rainfall 

 for^this period was 16 inches, and the number of wet days 97*8. 

 This amount is not very small ; the reputed dryness of Athens 

 is due to three other causes : ( i ) the considerable variation in 

 the annual fall ; thus in 1883 it amounted to 33 '3 inches, while 

 in 1 89 1 it was only 8"i inches, or half the normal value. The 

 dry and wet years follow with some regularity ; a very wet period 

 occurs generally about every seventh year. (2) The annual 

 range of the rainfall, which presents great irregularity. The 

 wettest month, November, has an average fall of 3'i inches ; 

 and the dryest, July, only 0*3 inch. From June to July the 

 rainfall is very insignificant ; at times there is none for three 

 months. (3) The intensity ; the falls being heavy, but of short 

 duration. It rarely rains for a whole day, generally speaking, 

 after a few hours of rainy weather the sky becomes quite clear. 

 From observations taken at 8 a.m., 2 and 9 p.m., it is 

 found that the amount of rainfall during the day is double what 

 it is during the night ; the maximum occurs during the after- 

 noon, owing to the greater frequency of thunderstorms at that 

 time. The great variation in the yearly rainfall is said to be due 

 to the different amount of humidity brought by the equatorial 

 air-current, according to the course it has taken in arriving at 

 Athens. 



A VALUABLE Catalogue (No. 155) of choice and rare books, 

 including selections from the libraries of the late Dr. Reginald 

 S. Poole, and Prof, de Lacouperie, has been compiled and 

 issued by Mr. Bernard Quaritch, 15 Piccadilly. 



At the recent meeting of the National Academy of Sciences' 

 held at Philadelphia, the following papers were presented : — 

 " On the Palaeozoic Reptilian Order of the Cotylosauria," by Prof. 

 E. D. Cope; "On a New Variable of Peculiar Character," 

 by Dr. S. C. Chandler (see " Our Astronomical Column," 

 p. 109) ; "On a Bone Cave at Port Kennedy, Pa," by Prof. 

 E. D. Cope ; " On Borings through the Coral Reef in Florida," 

 by Prof A. Agassiz ; "On the Alkali Uranates," by Prof. 

 Wolcott Gibbs ; " The 01indiad?e" and " New Campanuluriarv 

 Meduste," by Prof. W. K.Brooks; " The Filar Anemometer " 

 and "The Counter-twisted Curl Aneroid," by Prof Carl 

 Barus ; " On the Broadening of Spectral Lines by Temperature 

 and Pressure," by Prof. A. A. Michelson ; "On the Asteroids," 

 by Prof. A. Hall; and " The Early Segregation of Fresh- water 

 Types," by Dr. Theo. Gill. 



The fourth volume of Transac ions of the Rochdale Literary 

 and Scientific Society, covering the period 1893-1895, 

 has reached us. Included in it are papers on "The Birds in 

 Piethorn Valley," by Mr. W. Watts ; " The Rainfall in Rochdale 

 and the Neighbourhood," by Mr. J. R. Ashworth ; " The 

 Cold Weather at Facit, during the Winter of 1894-95," 

 with instructive diagrams, by Mr. T. S. Smithson ; and 

 Recent Discoveries in the Manufacture of Indigo," by 



