June 24, 1887.] 



SCIENCE. 



609 



ploys as the active material the hardening mix- 

 ture of oxide of lead and sulphuric acid, for which 

 letters patent were granted to him in the year 

 1882 (No. 4,303) ; and whilst this mixture is in a 

 pasty condition he moulds it into small cylinders 

 or rods of convenient length and thickness, either 

 by rolling, pressure through a draw-plate or tube, 

 or other convenient means, and then flattens them 

 on two opposite sides by pressure between two flat 

 boards or otherwise. After these flattened cylin- 

 ders have become sufficiently hard, they are placed 

 in rows in a casting mould of dimensions corre- 

 sponding to the size of the battery-plate required, 

 and at such distances apart and from the edges of 

 the mould as to give sufficient space for the quan- 

 tity of metal necessary to impart adequate strength 

 and rigidity to the plate. Suitable molten metal, 

 such as lead or an alloy of lead and antimony, is 

 then poured into the mould until the interstices 

 between the flattened cylinders are completely 

 filled. In this way a plate is obtained, in which 

 the active material is incased except on the flat- 

 tened sides of the cylinders ovei'laid with metal, 

 so that it cannot subsequently fall out during the 

 charging and discharging of the battery, or even 

 when subjected to considerable rough usage. 



— At a recent meeting of the Physical society, 

 London, Mr. C. V. Boys described some methods 

 of producing very fine glass fibres. The author 

 finds it best to use very small quantities at high 

 temperatures, and that the velocity of separation 

 should be as great as possible. To obtain a great 

 velocity, Mr. Boys used a cross-bow and straw 

 arrow, to the tail of which a thin rod of the sub- 

 stance to be drawn is cemented. The free end of 

 the rod is held between the fingers, and, when the 

 middle part has been heated to the required tem- 

 perature, the string of the cross-bow is suddenly 

 released, thus projecting the arrow with great 

 velocity, and drawing out a long fine fibre. By 

 this means fibres of glass less than one ten-thou- 

 sandth of an inch in diameter can be made. The 

 author has also experimented on many minerals, 

 such as quartz, sapphire, ruby, garnet, felspar, 

 fluor-spar, augite, emerald, etc., with more or less 

 success. Ruby, sapphire, and fluor-spar cannot 

 well be drawn into fibres by this process, but 

 quartz, augite, and felspar give very satisfactory 

 results. Garnet, when treated at low tempera- 

 tures, yields fibres exhibiting the most beautiful 

 colors. Some very interesting results have been 

 obtained with quartz, from which fibres less than 

 one hundred-thousandth of an inch in diameter 

 have been obtained. It cannot be drawn directly 

 from the crystal, but has to be slowly heated, 

 fused, and cast in a thin rod, which rod is attached 

 to the arrow as previously described. Quartz fibre 



exhibits remarkable properties, as it seems to be 

 free from torsional fatigue, so evident in glass and 

 metallic fibres, and on this account is most valua- 

 ble for instruments requiring torsional control. 

 The tenacity of such fibres is about fifty tons on 

 the square inch, 



— The London Times publishes a telegram from 

 Vienna to the effect that a Greek scholar, M. 

 Papageorgiu, residing in Philippopolis, has dis- 

 covered an ancient manuscript containing por- 

 tions of Aristotle's works. The manuscript is of 

 the fourteenth century, and contains one hundred 

 and eighty pages, which comprises four books of 

 the treatise ' On the heavens,' two books of ' On 

 generation and decay,' the first three books of 

 ' On the soiil,' and parts of the 'Sophistical refu- 

 tations.' The manuscript is in an excellent state 

 of preservation, the vellum being clean and strong, 

 and all the writing perfectly legible. There are 

 marginal annotations of the fifteenth century. 

 M. Papageorgiu, on completing his researches, 

 will publish an account of them in pamphlet 

 form. The chief point brought out thus far by 

 him is that the newly found manuscript differs 

 in some important particulars from Didot's and 

 other existing editions. Moreover, it contains ex- 

 tracts only from the genuine Aristotelian writings, 

 and nothing from the writings which are usually 

 held to be spurious. 



— J. Liznar (Wiener akad. Anzeiger, 1887) has 

 arranged and computed the observations on ter- 

 restrial magnetism of the international polar sta- 

 tions of Fort Rae and Jan Mayen, in order to in- 

 quire into the existence of a period of twenty-six 

 days of the magnetical phenomena. As the 

 periodical oscillations of the magnetical elements 

 are the greater the closer we approach the mag- 

 netical pole, the observations of Fort Rae, Cumber- 

 land Sound, and Jan Mayen were the most favor- 

 able for these researches. As those of Cumber- 

 land Sound were not published until the close of 

 last year, Liznar confined himself to arranging 

 the available material from Fort Rae and Jan 

 Mayen. The result' of his inquiries is, that the 

 amplitude of the period of the oscillations of dec- 

 lination is 55.1' at Fort Rae, 34.8' at Jan Mayen, 

 while it is only 0.4' at Vienna, and 1.4' at 

 Pawlowsk. The length of the period is 25.85 

 days, while former computations gave a value of 

 25.97 days. These results show that the rotation 

 of the sun, which is the probable cause of these 

 periods, has a far greater influence on the mag- 

 netical elements, as might have been anticipated 

 from observations in lower latitudes. 



— In Scrihner's magazine for July, Prof. D. A. 

 Sargent, M.D., of Harvard college, who is an au- 



