June 19, 1890] 



NATURE 



181 



The Konigsberg Physikalisch-Oekonomische Gesellschaft has 

 recently invited a comprehensive discussion of the observations 

 of ground- temperature at Konigsberg, published in the Society's 

 Schriften, as bearing on our knowledge of heat-movements in 

 the earth and their causes. Attention is called to a previous 

 work by O. Frolich, published at Konigsberg in 1868. For the 

 best treatment of the subject a prize of £1$ is offered. Papers 

 (in any language), with motto, to be sent in before February i, 

 1891. 



Science announces that Lieutenant J. P. Finley, of the U.S. 

 Signal Corps, has gone to San Francisco to take charge of the 

 Pacific Coast weather service. 



We learn from Science that a work of great importance 

 to navigators is to be undertaken in connection with the report 

 of the U.S. Eclipse Expedition to West Africa, under the 

 direction of Prof. D. P. Todd. This is the preparation of a 

 set of daily weather-maps of both oceans from October to May 

 inclusive, the entire period of the cruise of the U.S. steamship 

 Pensacola. The U.S. Ilydrographic Office calls attention to 

 the importance of the subject, and the exceptional opportunity 

 presented for utilizing the data already at hand, together with 

 such additional data as may be contributed for this purpose by 

 various Government offices and individual navigators. The 

 scheme determined upon consists in the preparation of a weather 

 map for each day at noon, Greenwich mean time, from October 

 I, 1889, to May 31, 1890, inclusive, for the entire area between 

 latitude 70° north and 60° south, longitude 20° east and 100° 

 west. In addition to the Greenwich noon observations that are 

 kept regularly for the Hydrographic Office by nearly two 

 thousand voluntary observers, it is earnestly desired that other 

 navigators of these waters, within the limits of time and place 

 mentioned above, may forward to that office such data from 

 their log-books as may be useful in this connection, selecting 

 those observations that come nearest to noon, Greenwich mean 

 time, and stating as many details as possible regarding wind 

 weather, state of the sea, and velocity and set of currents. 

 Data from land stations are also very important, especially such 

 as are not accessible in any published records. To make this 

 great unde. taking a success, however, there must be further and 

 cordial co-operation among the nations interested in the meteoro- 

 logy of this vast area, and among navigators of every nationality. 

 It has long been the desire of the U.S. Hydrographic Office to 

 begin the publication of a pilot chart of the South Atlantic and 

 west coast of South America, and the present undertaking will 

 furnish an admirable basis for this work. 



A PAPER on the Mannesmann weldless tubes was lately 

 read before the Society of Arts by Mr. J. G. Gordon, the 

 chair being occupied by Sir Frederick Bramwell, who referred 

 to the importance and interest of the subject, and to the ex- 

 traordinary means by which the desired result was attained. 

 The process consists in the solution of a purely kinematical 

 problem, viz. the arranging of the velocity ratio of a pair of 

 aconoidal rolls so as to change a solid piece delivered to them 

 at one end into a hollow tube passed out at the other. These 

 rolls revolve at about 200 to 300 revolutions per minute, and by 

 their action on the hot and therefore plastic steel stretch it 

 and make a hollow in the centre. The substance of the metal 

 must be sufficiently homogeneous and plastic, and, in passing 

 through the rolls, it undergoes a violent twisting and stretching 

 action. The bar, in fact, in its passage through the rolls, is 

 twisted as a thread is twisted in a spinning-machine, the mate- 

 rial being drawn from the interior. This action was illustrated 

 by one of the exhibits, which consisted of a bar, the ends of 

 which were slightly drawn down under the hammer, so that the 

 rolls could not act on them. A hollow was thus produced in 

 the solid bar of metal, the contents of which were tested by 

 NO. 1077, VOL. 42] 



Prof. Finke, of Berlin, and found to contain 99 per cent, of 

 hydrogen of its total volume ; the remaining i per cent, he 

 considered to be probably nitrogen. In the carrying out of the 

 process, 2000 to 10,000 horse-power is required for from 30 to 45 

 seconds, according to the dimensions of the tube. Although 

 this is all the time actually required to convert a bar 10 to 12 

 feet long and 4 inches in diameter into a tube, a certain amount 

 of time is required to adjust the guides, to deliver the bar to the 

 rolls, and to remove the finished tube. The time so spent is 

 employed to accumulate energy in a fly-wheel 20 feet in dia- 

 meter, weighing 70 tons, and revolving 240 times in a minute, 

 the periphery of which therefore revolves at 2*85 miles per 

 minute ; by this means, a steam-engine of 1200 horse-power is 

 quite sufficient to do the work. A peculiar feature of these rolls 

 is that the resulting tube is a test of the material and process. 

 If the metal is homogeneous throughout, and well melted, 

 well rolled, and carefully heated, it makes a perfect tube ; but 

 if there is a flaw in the metal, or if it has not been properly 

 heated, the rolls cannot make a tube out of it. The paper, 

 which was illustrated by photographs of the mills and engines, 

 led to a very interesting discussion, in which Sir Frederick 

 Bramwell, Prof. A. B. W. Kennedy, Mr. Alexander Siemens, 

 and others took part. 



Messrs. J. and A. Churchill have issued the fifth edition 

 of Prof. F. Clowes's "Treatise on Practical Chemistry." The 

 present edition contains several emendations and additions. 

 The author explains that the work is intended to furnish a 

 course of laboratory instruction in practical chemistry, which 

 may precede the higher training of the professional and pharma- 

 ceutical chemist and the medical man, and the more special 

 training of the technical chemist and the chemical engineer. 



The sixth volume of " Blackie's Modern Cyclopaedia," 

 edited by Dr. Charles Annandale, has been published. The 

 volume begins with " Mona," and ends with " Postulate." The 

 articles, like those of the previous volumes, are remarkably 

 clear, concise, and accurate. 



The third number of the "Indian Museum Notes" consist- 

 of a careful paper on silkworms in India, by Mr. E. C. Cotes. 

 The author confines attention to those species which are actually 

 utilized in India for the production of silk. 



Mr. W. F. Kirby, author of " A Synonymic Catalogue of 

 Diurnal Lepidoptera," will publish shortly with Messrs. Gurney 

 and Jackson, Mr. Van Voorst's successors, " A Synonymic Cata- 

 logue of Neuroptera Odonata or Dragon-flies." He hopes to 

 bring out afterwards the first volume of his" Catalogue of Lepido- 

 ptera Heterocera," a work which has engaged his attention for 

 nearly twenty years. 



The editor of the Naturalists' Gazette has in the press an 

 " Illustrated Hand-book of British Dragon-flies," which will 

 contain a full description of all the species indigenous to the 

 British Isles, in addition to a quantity of other information. 



A new gas, methylene fluoride, CHjFo, has been obtained by 

 M. Chabrie, and a preliminary account of it will be found in the 

 current number of the Comptes rendus. Its chlorine, bromine, 

 and iodine analogues, CHjClj, CH2Br2, and CHj^j* ^^^^ '°"g 

 been known. Methylene iodide is a liquid at ordinary tempera- 

 tures which solidifies about 4° C. to brilliant leafy crystals. The 

 liquid boils at 182°. Methylene bromide is a liquid boiling at 

 81°, and the chloride is also a liquid boiling at 41°. The fluoride, 

 completing the graduation of the series, is now shown to be a 

 gas. It is obtained by heating the chloride with silver fluoride. 

 Methylene chloride is generally prepared from methyl iodide, 

 which is placed in a retort, covered with water, and a 



