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of "hundreds of motor-cars crashing through the trees." The storm occurred at about 4 p.m. in Devon, at 5.40 to 5.50 p.m. in South Wales, at 7.35 to 7.45 p.m. in Shropshire, and at 9 p.m. in Cheshire. progress of the central area of the storm is given as 36 miles an hour No absolute measurement of wind velocity was secured, and a similar absence of barometer records is mentioned, with the exception of one station only a few yards from the South Wales track, where the record shows a fall of pressure from 29.20 in. to 28.91 in., followed by an almost immediate rise.
THE Scientific American for February 13 contains the third of the series of articles entitled "Doing without Europe," to which we referred in these columns a month ago. The principal object of the articles is to show how vast are the mineral resources of the country and how little they are utilised. The present article deals mainly with the barium salts used in the manufacture of paint. Up to the commencement of the present war these had been imported from Germany, but one of the largest paint manufacturers of New York has commenced manufacturing them from an ore found in Tennessee, and now turns out 15 tons a day. In respect to potash salts, of which the annual import from Germany exceeded 3,000,000l., the United States Government has directed attention to the natural deposit of the salts at Searles Lake, California, and a manufacturing plant has been set up there the success or failure of which will be watched with interest. Soda, magnesia, and several other substances are also mentioned as being found in abundance in the country, and as only requiring working to supply all requirements.
AN interesting paper on the internal-combustion engine in the oil field was read at the Institution of Petroleum Technologists on March 18 by Mr. F. G. Rappoport. It appears that the steam engine still largely holds its own despite its inefficiency, the reason for this being in the special character of the work to be done in boring and baling oil wells. Great flexibility in power and speed is required, and while electric power distributed from central stations is ideal from other points of view, electricity lacks that flexibility at the well which makes steam power so convenient. The oil engine has created a large and important sphere of its own by facilitating profitable operation of a large class of wells having a small yield. Such wells had formerly to be closed, and the advent of the oil engine with its low fuel-consumption has rendered possible their operation. The oil engine is well adapted for outlying districts and for prospecting work; the Binagadi oil field, without adequate water supply, is worked almost entirely by means of oil engines. The new Ural and Biellik districts in Russia are largely worked by oil engines. Applications of the gas engine are also discussed, and reference is made to an engine made by Messrs. Tangye, which can be run as a gas engine, or as an oil engine, by alteration of certain parts. Several of these engines are in successful operation on the Baku oil field.
The comet lies approximately between y Ophiuchi and Serpentis.
Herr K. Hillebrand, in an Ephemeris Circular of the Astronomische Nachrichten (No. 478), publishes the elements and ephemeris of the periodic comet of Winnecke for its appearance in the current year. The latter extends from April 16 to the end of August.
A search ephemeris for Tempel's comet (Ephemeris Circular, No. 479) is given by Herr J. Braae. In 1910 this comet was not seen, but it is pointed out that this year it will be a little more favourable for observation. The ephemeris is extended to the end of June of the present year, and will be continued later.
THE STRUCTURE OF THE HY LINE IN STELLAR Spectra. -In this column for July 31 of last year attention was directed to a paper by Herr K. F. Bottlinger, in which was shown the result of a study of the intensity distribution of lines in many of the brighter stars. In a recent number of the Astronomische Nachrichten (No. 4788, vol. cc., No. 12) Dr. Adolf Hnatek gives his conclusions from rather a similar investigation. The author has measured both the intensity (Linientiefe) and breadth (Linienbreite) of the Hy line in several bright stars, and summarises the values deduced according to the spectral types of the stars examined. Thus, in the case of the line-width the following are mean values in Angström units which he has deduced.
Summarising the values of the line-intensity (Linientiefe), he points out that they show also a similar relation to the spectral types; these intensity values are added in the last column of the above table. The paper contains also a number of curves of the Hy lines in the individual stars arranged in groups according to their spectral classes. While the above investigation deals only with one line and a small number of stars, the author hopes to extend the research to more lines and stars in order to deduce results of a more definite and trustworthy value.
THE HARVARD COLLEGE OBSERVATORY REPORT.-The annual report of the director of the Astronomical Observatory of Harvard College for the year ending September 30, 1914, indicates the completion of a large amount of work in both observation and publication. Prof. E. C. Pickering refers in the first place to the principal work of the observatory, namely, its publications and the importance of issuing these as soon as possible to prevent loss by fire. Thus observations from 1892-1912 with the 15-in. equatorial, from 1888-98 with the 8-in. transit circle, and from 1898-1912 with the 12-in. meridian photometer are now printed, and the discussions are in progress. The director directs attention to the improvement in photographic processes resulting in the replacement of practically all visual work. The report then describes in more detail the work of the Henry Draper Memorial, the principal research of which is the New Draper Catalogue; last year Miss Cannon classified 60,386 spectra, making a total of 160,541. The activities of the Boyden department, the Bruce photographic telescope, and the Blue Hill Meteorology Observatory are briefly summarised, while among the many items mentioned under the heading "Miscellaneous" the work of Prof. W. H. Pickering at the Mandeville Station, in Jamaica, is described, much time having been devoted to the study of the planet Mars during its recent opposition.
STAR CHARTS FOR METEOR Observers.-One of the contributions to the January number of the Journal of the Royal Astronomical Society of Canada (vol. ix., No. 1, p. 7) is entitled "A Gnomonic Star Atlas," and contains a set of thirteen maps, prepared by Mr. Reynold K. Young, intended to facilitate the observation of meteors and the plotting of their paths. The method of the projection of the map is such that great circles in the sky are equivalent to straight lines on the map, thus making the plotting of the meteor trails more easy. The maps are devoid of unnecessary detail. The positions of the stars are given for the epoch 1900 correct to within one-tenth of a degree, and all stars down to 5th magnitude and the brighter variables are included. A good margin of overlap has been allowed in each map, which should prove very useful.
FLUCTUATIONS OF TEMPERATURE IN EUROPE AND AMERICA.
MR. H. ARCTOWSKI, in a paper published in
vol. xxiv. of the Annals of the New York Academy of Sciences, considers the problem of variation of temperature over the whole earth. After a brief statement of the general problem and the methods by which it may be attacked, he explains that he could not deal single-handed with the arrangement and discussion of the actual values even over the whole of the northern hemisphere, and confines himself to the detailed survey of the variations over North America and Europe. He also compares the results with one or two representative equatorial and southern hemisphere stations. From a study of the values at one of these, Arequipa, in Peru, he deduces that the temperature changes are partly of a short period of about fifty-five days, brachypleionian waves; partly of a long period of twenty years or so, macropleionian waves; and partly of an intermediate period of between one and two years, pleionian waves.
In dealing with the longer periods the normal annual variation is eliminated by taking a series of means for twelve months beginning with each consecutive month of time. For the European stations he finds that the continental ones resemble Arequipa in having marked pleionian waves, while those sta
tions near the Atlantic are characterised mainly by brachypleionian variations.
In an earlier paper Mr. Arctowski dealt with the period 1891-1900, and he takes the mean values for this period as normals, and plots on maps the difference from normal of the values during each year of the decade 1900-09. The areas where the differences are positive he cails thermopleions, and the areas of negative differences antipleions. He finds that certain years, in particular 1900, 1908, are characterised by thermopleionian areas, while others, such as 1904, 1907, are years of antipleions. The most important cause of these differences is the variation of solar radiation, but there are also supplementary causes such as the presence of volcanic dust in large quantities, or exceptional ice conditions in the polar regions.
Many of the maps which illustrate the results of the investigation are on a very small scale; the course of the thermopleions and thermomeions is obscured by the attempt to show relatively microscopical geographical details.
Mr. Arctowski finds it astonishing that after all the efforts which are made to organise and maintain meteorological stations all over the world, the actual results of the work are so inaccessible. Even for the area with which he dealt he could only get much of the data by writing personally to the directors of the different meteorological institutes. This is a defect which will be remedied when meteorologists of different countries undertake to contribute to a central
bureau representative regional values based on a selection of stations which can only be chosen satisfactorily by the local organisation.
There is another defect which is almost more
serious, viz., the lack of continuity in the records for individual stations due to changes of situation or instruments. For example, Mr. Arctowski finds that the difference of temperature between Chicago and Milwaukee was nearly 4° F. in the decade 1873-82, while in the decade 1896-1909 the difference was only 2° F. The change is almost certainly due to change of instrument or site, and as it is of the same order of magnitude as the changes with which he deals, it indicates the need for great caution.
The difficulty of securing comparable continuous records is indeed one of the most serious problems with which organised meteorology has to deal.
REFINING GOLD BY ELECTROLYSIS.1 THE problem presented by the necessity of refining gold was one for which a solution was sought at least as early as the time, about B.C. 700, when coins were first manufactured in the Western world. Apart from toughening or the removal of base metals, which was sufficiently cared for by the ancient process of cupellation, it is clear that some measure of success attended the efforts made to part gold and silver. Thus, some of the ancient Greek coins containing 997 or 998 per 1000 of gold. The earliest parting process used was one of cementation, which was succeeded by the nitric acid process. At the present day chlorine is the predominant agent for parting gold from silver in Australia, electrolysis in America, and sulphuric acid in Europe.
The electrolytic process was brought forward by Charles Watt, at Sydney, in 1863, and was first put into operation by Wohlwill at Hamburg in 1878 and by Tuttle at the Philadelphia Mint in 1902. In the gold chloride process the solution used in the bath
1 Abstract of the presidential address delivered before the Institution of Mining and Metallurgy on March 18, by Sir T. K. Rose.
contains gold in the form of chloride and some free hydrochloric acid. Gold is dissolved at the anode, under the action of a current of electricity, and deposited in a pure state at the kathode. Other metals are also converted into chlorides at the anode, and either remain in solution, or pass into the anode slime. When silver is contained in the anode, it is converted into silver chloride which in part dissolves, in part falls to the bottom of the cell, and in part adheres to the anode, forming an insoluble coating. result of the coating is that the free area of the anode is reduced, the density of the current becomes greater per unit area of effective anode surface, and chlorine is evolved unless a very small current is used. According to general experience, if more than 6 per cent. of silver is present in the bullion of the anode it is necessary to brush the silver chloride from the anodes, and accordingly this percentage is seldom exceeded in practice.
square metre, the gold is deposited in a coherent form, which is easily washed, and is malleable after being melted. The density of current now employed in practice is below 1000 amperes per square metre, and the anodes occupy about a week in being dissolved. With a current of 5000 amperes, .the anodes would be dissolved within the limits of a working day and a saving in interest, and in the difficulties of daily stocktaking, would be effected.
One of the merits of the electrolytic, process is that the refined gold is always malleable and fit for use in the arts, and another is that any platinum contained in the gold is extracted. This is becoming of some importance in view of the high price of platinum and of the fact that nearly all rough gold bullion, including that from the Transvaal, is now known to contain that metal. According to the experience in the United States mints (Fig. 1), it is cheaper to refine gold by electrolysis than by sulphuric acid.
The usual amount of free hydrochloric acid present in the bath varies from 3 to 10 per cent., but according to the results of experiments now put forward by Sir Thomas Rose some advantages are obtained by the use of stronger solutions. Thus in a bath containing 29 per cent. of free hydrochloric acid, a current of 5000 amperes per square metre of anode surface can be used without causing chlorine to be evolved at the anode. Under these conditions the proportion of silver in the anode may be raised to at least 20 per cent. without difficulties being encountered. The heavy current causes the silver chloride to split off from the anode, and also prevents gold from entering the anode slime, principally because no monochloride of gold is allowed to form.
Similar advantages occur in the deposition of gold at the kathode by the use of a solution containing 20 per cent. of gold as chloride instead of the usual 3 to 5 per cent. With a current of 5000 amperes per
[B. P. Wirth.
BIRD-MIGRATION IN 1913.1
WE have before us
the ninth of a projected series of ten reports setting forth the imposing mass of data regarding bird-migration. collected by the committee appointed for the purpose by the British Ornithologists' Club. Once the final volume, dealing with the autumn of 1913 and the spring of 1914, has appeared, we may expect a publication of greater importance, summarising the vast amount of material collected by ten years' labour. In the meantime no attempt is made to draw conclusions from the facts which are published, but a few points about the movements of 1912-13 may here be selected for notice.
The autumn of 1912 appears to have been remarkable for the early dates at which the Thus a swallow
migrations of several species began. was noted at the Bell Rock Light in the Firth of Tay on July 4, and willow-warblers at the same place two days later. As early as June 25 a large flock of starlings had been seen flying west in the evening at Spurn Head Light. On the nights of July 14-15 and 15-16 swifts were recorded from the Lundy North Light (British Channel) and the Hanois Light (Channel Islands) respectively.
The great movements, however, do not seem to have begun until mid-October, and the migrations observed during the first three weeks of November were of extraordinary magnitude. Almost every night during that period half-a-dozen different light-stations record the passage of large numbers of birds, notably skylarks, starlings, and various species of Turdus.
1 Report on the Immigrations of Summer Residents in the Spring of 1913; also Notes on the Migratory Movements and Records received from Lighthouses and Light-vessels during the Autumn of 1912. (Bulletin of the British Ornithologists' Club, vol. xxxiv., December, 1914.)
The winter which followed was marked by comparatively high and uniform temperatures. Consequently many summer-visitant birds do not seem to have quitted some of the southern and western districts, while others were recorded as returning at unusually early dates. The spring immigration proper is stated to have lasted from March 6 until June 6, reaching its. height between April 14 and May 11.
Attention is directed to the very long period covered by the immigrations of certain species as contrasted with those of others. On one hand we have swallow (March.8 to May 20), sand-martin (March 13 to May 15), chiffchaff (March 6 to May 8), and wheatear (March. ie to May 12). On the other we have the reed-warbler (April 18 to May 5), wood-warbler (April 9 to May 11), and nightingale (April 13 to May 5).
A special feature of the report is the long list of records emanating from the Caskets Light in the Channel Islands. This station is exceptionally favourably situated, and was expected to furnish very important data. Unhappily, the committee had formerly been unable to induce the light-keepers to take the matter up. The desired result has been brought about, however, by the transfer to the Caskets of an enthusiast in the work, Mr. R. E. Wilson. His contributions to the present report are very valuable. A special summary of the records relating to this station is promised for the next report.
The publication under discussion is even bulkier than its recent predecessors, but the data are set out in the same clear and orderly manner. As usual there are numerous charts and a useful summary of the meteorological conditions prevailing during the period covered by the migration records A. L. T.
THE INSTITUTE OF METALS.
N spite of the war, both the number and quality of the papers presented at the annual meeting of the institute on March 18 and 19 were well up to the average. Naturally, in the circumstances, the contributions were furnished mainly by what may be termed the "academic" workers in non-ferrous metallurgy. Moreover, although the attendance of members was small, the discussions were always interesting and well-sustained. Unfortunately the president of the institute, Engineer Vice-Admiral Sir Henry Oram was prevented by his onerous official duties at Whitehall from presiding at the proceedings, and his place was filled at the last moment by one of the vice-presidents.
The paper by Prof. A. C. Huntington, on the effects of heat and of work on the mechanical properties of metals, gave rise to an interesting debate, and a spirited reply by the author. It describes a machine devised by him several years ago for the purpose of investigating these effects while the metals are being subjected to alternating bending stresses, such as occur in the firebox of a locomotive. No attempt was made to reproduce the somewhat complicated movements which occur there, but the metal or alloy was held rigidly at one end, and "subjected to a to and fro movement at the other end in a single plane at right angles to its axis." Both as regards the extent of the movement and the range of temperature investigated, the experiments were made to conform broadly to the kind of conditions that obtain in locomotive fireboxes. Various kinds of commercial copper, and a copper alloy containing upwards of 5 per cent. of nickel and iron, were tested in this way. The outstanding feature of the curves, the co-ordinates of which are temperature and the number of revolutions required to crack and break the specimens, is the large number of maxima and minima which the author
interprets from his data. For copper he gives five maxima and five minima. The fact, however, that these do not by any means always correspond to observed points gave rise to considerable criticism in the discussion and to a variety of alternative interpretations. From the fact that annealing greatly reduces the maxima and minima the author concludes that work plays an important part in emphasising transformation points, and goes so far as to say that "except in the case of phase changes in alloys, mechanical tests are to be preferred to heating and cooling curves as a means of studying changes of state with temperature." Even if this claim is admitted, it limits the application of such methods to ductile alloys, but not unnaturally objections were voiced to a statement which has certainly not been proved.
Dr. Rosenhain, in his paper, entitled Some Appliances for Metallographic Research," described optical instrument for the levelling of metallographic specimens, a new method of taking thermal curves, and a plotting chronograph, the last-named having been devised with the help of the Cambridge Scientific Instrument Co. These appliances have been originated by Dr. Rosenhain at the National Physical Laboratory. Great interest was expressed in them, particularly in the design of furnace for taking thermal curves. In order to obtain as nearly as possible a constant rate of heating or cooling of the metallic specimen a tubular furnace is erected vertically in which a "regular temperature gradient is established and steadily maintained while the specimens whose heating and cooling curves are to be taken are moved at any desired rate from the cold to the hot end of the furnace or vice versa." Heating and cooling curves obtained in such a furnace and in conjunction with the plotting chronograph show that very satisfactory results have been obtained. The power consumption with the hot end at 1000° C. is a kilowatt. No figures for higher temperatures have been given, and it will be interesting to have those stated when they have been determined.
With regard to the plotting chronograph, the author's endeavour has been to originate an instrument which shall furnish an inverse rate curve "plotted to an adequately open scale." The apparatus is not as yet entirely self-recording, but represents a considerable step in this direction, and it gives the curve obtained with no other human intervention than the periodic tapping of a key.
The paper by Prof. Read and Mr. Greaves, of University College, Cardiff, contains an account of their investigations on nickel-aluminium and nickelcopper-aluminium alloys, more particularly the light alloys of the last-named group, and is a continuation of their earlier work on the heavy alloys of the same metals. They find that, as regards the ternary alloys, copper and nickel can replace each other without the resulting properties being affected, and, in fact, that certain characteristics of the alloys are determined by the total percentage of copper and nickel present. they point out, this is intelligible in view of the fact that the two metals possess almost identical densities and very similar atomic volumes. Moreover, micrographic analysis shows that the internal structure of the alloy scarcely alters when the one metal replaces the other. Inasmuch as nickel costs about three times as much as copper, and its melting point is nearly 400° C. higher, it is clear that it cannot compete with it economically in the case of such alloys, except perhaps in a few instances where the need for resistance to corrosion in certain liquids is sufficiently imperative to outweigh considerations of expense.
A very useful compilation of etching reagents and their applications to metallography was presented by
Mr. O. F. Hudson. This work had been undertaken at the request of the Publication Committee of the institute, and in preparing it Mr. Hudson received and incorporated methods adopted by well-known workers both in America and this country. The paper deals more especially with the final stage in the preparing of specimens for microscopic examination, but as the author points out, the effects of previous operations must always be borne in mind. There is now an increasing consensus of opinion among the most skilled metallographers that grinding on mechanically-driven discs produces too severe an alteration in the surface structure of a metal or alloy, which is likely to create difficulties in their microscopic interpretation after etching, and that hand grinding, although slower, is much more trustworthy. This is neither more nor less than a return to the technique of the late M. Osmond, whose skill in the preparation of a specimen for microscopic examination has never been surpassed. discussion on Mr. Hudson's paper was in a high degree illuminating, and showed the institute members at their best. When the complete paper and discussion are published they will certainly be a standard work of reference.
Four other papers were submitted. Of these, that by Mr. Whyte, on the microchemistry of corrosion, and that by Mr. Haughton, on the constitution of the alloys of copper with tin, were read and discussed. The remaining two were taken as read, and will be discussed by written communications.
H. C. H. CARPENTER.
SUPPLIES OF LABORATORY AND OPTICAL GLASS APPARATUS. REPORTS OF THE BRITISH SCIENCE GUILD.
HE British Science Guild has just issued two reports dealing with matters of national moment at the present time. One is concerned with the provision of glass apparatus for educational purposes, and the other with optical glass and the position of technical optics generally in this country. The reports are here reprinted, and it will be seen that they are both informative and helpful. First, with regard to laboratory ware, it appears that, as the result of an inquiry instituted by committees of the guild, working in co-operation with the Association of Public School Science Masters, about three-quarters of the schools or other bodies requiring laboratory glassware have undertaken to use British glass during the war, and for a period of three years after, provided that the price is not prohibitive. As explained in a letter to NATURE of February 18 (p. 670) the British Laboratory Ware Association has made arrangements for the supply of laboratory glassware and similar materials from British manufacturers. The British Science Guild has, by its action, presented the association and British glass manufacturers generally with an assurance of support which should be of the greatest value to them.
The report of the Technical Optics Committee of the guild should cause serious attention to be given to the establishment of a British Institute of Technical Optics. In the last annual report of the guild it was pointed out that this necessity had been impressed upon the education department of the London County Council continuously during the past twelve years. Scientific experts, leading members of the optical industry, and educational experts have combined to urge the paramount importance of the definite proposals which have been formulated, but the scheme still hangs fire. Meanwhile our scientific and industrial rivals on the Continent, taking note of successful
developments on a small scale which have been originated here, have gone forward to new developments with increased vigour and with highly successful results.
(1) PROVISION OF GLASS APPARATUS FOR EDUCATIONAL PURPOSES.
In the past practically all the glass and procelain apparatus used in chemical laboratories in this country has been manufactured in Germany and Austria. As the supply is now cut off and the stocks held by British dealers are almost exhausted, the problem of obtaining apparatus for educational and technical purposes has become a serious one.
The Joint Committee is informed that efforts are now being made by several firms to introduce the manufacture of glass apparatus into this country, and being in hearty sympathy with these efforts, it has considered in what way the British Science Guild may best assist. In these efforts the committee has cooperated with the Association of Public School Science Masters, and has taken action along two main lines, viz. :
(A) Endeavouring to obtain assurances of support for British makers of educational glass ware after the war as well as now.
(B) Obtaining information from educational institutions respecting the principal types and sizes of glass apparatus in greatest demand.
(A) Assurances of Support for British Makers of Scientific Glass Ware.
It is understood that the efforts during the last three months by certain British glass manufacturers have been attended with satisfactory results as regards the quality of the products. Economic and manufacturing conditions have prevented British glass apparatus being sold at so low a price as has been paid in the past for German material. As these conditions will probably remain unchanged, British manufacturers have been naturally disinclined to expend the necessary capital in establishing the proposed new industry here while there is every likelihood that they will be undersold in the British market by their competitors when the war is over. The Joint Committee is informed that this has acted as a strong deterrent to British glass manufacturers contemplating the production of scientific glass apparatus.
The Joint Committee therefore has endeavoured to ascertain how far it is probable that educational institutions would undertake to buy only British-made glass and porcelain apparatus during the war, and for a period of three years after.
Inquiries were made in this direction by the hon. secretary of the Association of Public School Science Masters, who is a member of the Joint Committee. from the headmasters of all schools represented on the Headmasters' Conference. Out of the hundred and ten (110) schools so represented, no fewer than seventyeight (78), i.e., 71 per cent., have definitely promised to authorise their science staffs to purchase, as far as possible, only British-made glass apparatus during and for a period of three years after the conclusion of the war. As these promises have been received from almost all the largest schools, both boarding and day, it may be assumed that manufacturers as well as dealers will receive adequate support from the "conference schools."
The guild also issued about 750 letters of inquiry
(a) Local education authorities.
(b) Governors of secondary schools.
(c) Governing bodies of technical institutions. (d) Senates of universities and university colleges, and has received a very large number of replies.