5o8 



SCIENTIFIC NEWS. 



[June I, lE 



mous trepan works and moves regularly, and almost 

 without noise. This tool, as used in the Place He'bert, 

 v/eighs about four tons, but in wells of 4 metres in 

 diameter, like those used at Konigsborn and Gelsen- 

 kirchen, it reaches nearly 27 tons. It is raised up about 

 16 inches from ten to fifteen times a minute, and falls 

 back with all its weight upon the bottom, which it reduces 

 to powder. 



Sometimes accidents happen ; the tubes are crushed or 

 flattened at great depths. They have then to be ex- 

 tracted and raised. A length of more than 100 yards of 

 tubing, weighing nearly 60 tons, was jammed in this 

 manner at the Place Hebert, and it required nine years 

 for its removal. 



Sometimes dynamite is used to break up the parts, 

 which are then extracted by powerful claws. But at 

 these great depths, and under enormous pressures of 

 water, explosives act badly. Charges of 30 lbs. of dyna- 

 mite merely raise a column of water and let it fall back 

 again. These pressures of 600 yards and upwards are 

 so powerful that a piece of straw, carried to the bottom 

 of the well by the borer and then brought up agam in 

 cleansing, becomes as heavy as metal, and falls to the 

 bottom of water like lead. 



•S»!^^5tf-» 



THE ELECTRIC ORGAN OF THE 

 SKATE. 



FOR centuries naturalists have been interested in, and 

 puzzled by, the electric organsof fishes, and notwith- 

 standing the great advances of recent years, we are still 

 unable to account for their existence. Mr. Darwin con- 

 sidered the electric organs as one of the special difficulties 

 of the theory of natural selection, and so they continue 

 to be at the present day, for, to use Mr. Darwin's words, 

 it is impossible to conceive by what steps they have been 

 produced. 



But although it has not yet been possible to explain 

 how these organs first originated, there is no longer any 

 doubt as to their structure and development. Some 

 years ago a Russian naturalist (Professor Babuchin) 

 discovered that the electric organ of the torpedo was 

 derived from tissues which, under ordinary circumstances, 

 would have given rise to muscular fibres ; and quite 

 recently Professor Ewart, of Edinburgh, by studying the 

 electric organ of the common skate (Raia batis) has 

 followed every step in the process of conversion of simple 

 muscular fibres into extremely complex electric discs. 



From an abstract* of a paper recently read at the 

 Royal Society, it appears that there is no indication of 

 an electric organ in the young skate until it reaches a 

 length of three or four inches. When this size is 

 reached, some of the muscular fibres at each side of the 

 tail of the skate lose their elongated form, and after 

 passing through a club or mace stage, give rise to shallow 

 cup-shaped bodies, which are soon transformed into 

 mushroom-like structures, each with a long slender 

 muscular stem. One stage follows another, until there 

 is eventually produced, in great part from the original 

 muscular fibre, a relatively large disc consisting of three 

 important layers, viz. : (i) in front an electric plate 

 (which corresponds to the motor plate of muscles) in which 

 a countless number of extremely delicate nerve fibrils 

 terminate; (2) a thick striated layer derived from the 

 head of the club, and made up of numerous fibr ils, 



" Nature," 17th May, 1888. 



having a sinuous or wavy arrangement ; and (3) of an 

 alveolar layer, consisting of beams running in all direc- 

 tions to form an irregular network with blood vessels, 

 and gelatinous tissue filling up the meshes. 



The transformation of the muscular fibre into an 

 electric disc seems to occupy a considerable time, and, 

 even when the disc is completed, a remnant of the 

 original fibre may persist in the form of a delicate ribbon- 

 shaped appendage. 



But in addition to working out the development of the 

 common skate. Professor Ewart has discovered that 

 there is considerable variation in the structure of the 

 electric organ in the skate genus, and especially that in 

 several skates the electric organ is made up of beautifully 

 moulded cup-shaped bodies which somewhat resemble 

 the " cup " of the familiar " cup and ball." A paper 

 giving an account of the structure of these " electric 

 cups," was read on the 17th May at the Royal Society. 

 The cups seem to be arranged to form two electric spin- 

 dles, one at each side of the tail. Each cup consists of 

 a thick outer layer or cortex studded with large nuclei, 

 a median striated layer, and a thin lining — the electric 

 plate. The cavity of each cup is occupied with nerve 

 fibres, which as they proceed towards the electric lining 

 divide again and again, and finally terminate in delicate 

 loops or circles. 



When Professor Ewart has communicated the further 

 results of his investigations, it may then be possible to 

 offer some explanation as to how muscular fibres came 

 to be converted into electric organs, and account for the 

 so-called "pseudo-electric " organ of the skate having a 

 most complex structure, while it appears to have no 

 possible function. 



As long as the origin of electric organs continues a 

 profound mystery, quite beyound the reach of the great 

 theory of natural selection, these structures are likely 

 to exercise not a little the minds of biologists. 



THE APPLICATION OF PHOTOGRAPHY 

 TO METEOROLOGY. 



IN December, 18S7, a series of large photographs, 

 taken from the Pic du Midi, with a view to the regis- 

 tration of meteorological phenomena, were presented to 

 the French Academie des Sciences by M. J. Janssen. In 

 the beginning of October last, M. Janssen's studies on the 

 electric absorption of oxygen induced him to spend some 

 time at the observatory at the summit of the Pic, then 

 under the management of M. Vaussenat, and while there, 

 his work having brought him into contact with a clever 

 photographer from Pau, who chanced to be then at the 

 Pic, it occurred to him that he might avail himself of the 

 intelligent aid of this M. Lamazouere to obtain some 

 photographs of the atmospheric phenomena which could 

 be so favourably observed from that elevated station. 

 His principal aim in the work was to attract more 

 universal attention to the important services which he 

 felt photography might render to meteorologists and 

 observers. 



M. Lamazouere having willingly acceded to M. Janssen's 

 proposal, they sent for a large number of 30-40 plates and 

 other necessary materials, and commenced to take photo- 

 graphs of every interesting phenomenon which they 

 witnessed during one week, the above-mentioned series 

 being the result of their combined eftbrts. Four of the 

 photographs — one of which we reproduce — of this 



