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which for ordinary watch-making is of prime importance. quality; the annual saving is certainly 10,000!., and is To resume those considerations. At the end of 1896 I found likely to become 20,000l. or 30.000l. Competition, morethat when an alloy containing 24 per cent. of nickel passes is so keen in the trade that a diminution of prices from the non-magnetic to the magnetic state, its modulus of passes at once from the manufacturer to the consumer, so elasticity undergoes a diminution of 10 per cent. This change that the public gains the whole advantage of it. is the more remarkable inasmuch as the limit of elasticity Another application in chronometry, although its advanis simultaneously raised, as was shown by Hopkinson. I tages from a monetary aspect are insignificant, seems to me was intending to study the same change in invar when of greater interest, because it appeals to a higher range M. Thury at Geneva and M. Paul Perret at La Chaux of thought, and represents an advance in a region in which de Fonds, after my first publication, established for the perfection had apparently been reached. alloy the singular fact of a positive variation of Young's In 1833 the celebrated English watchmaker Dent dismodulus with increasing temperature. A systematic in- covered that a chronometer regulated for two extreme vestigation of the change by M. Perret and myself led us temperatures gains at intermediate ones, and the correction to results which, completed by the theoretical views which of " Dent's error," as it is called, has exercised the in. were developed, permitted me to assign to the total variation genuity and invention of the best watchmakers. In England of the modulus of a nickel steel endowed with reversible particularly, the country par excellence of marine chronoproperties a course indicated by the curve in Fig. 7. Point metry, great efforts have been made to introduce correrA has the same significance as in the curve of Fig. 1, and tions for this error. The auxiliary systems of Loseby, of two regions of variation in a normal sense are shown, Kullberg and others have permitted the attainment of between which lies a region of abnormal variations con- great accuracy, but at the expense of a considerable increase nected with the first by two confluent curves.

in price and of complications which are not exempt from The existence of these confluent curves has a great im- | inconveniences. The cause of Dent's error is almost portance for horology. The necessity of fitting good entirely the non-linear variation of the elasticity of the watches with a bimetallic compensation balance arises steel of which the hair spring is composed. The curve OH.

Fig. 8, represents this variation. The action of the balance is proportional to the difference of the expansions of the metals composing the bimetallic ring; if we represent the expansions of steel and brass by the curves OS and OB it

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will be seen on referring to the numerical formulæ whenoe these curves are obtained that, whilst their average inclin

ation is very different, the variation of this inclination is Fig. 9.--Compensation with nickel-steel-brass balance.

nearly the same. The variation of the difference of inclin

ation is therefore nearly zero, and the curve giving the almost exclusively from the need of securing comparable difference of the expansions practically becomes the straight rates at different temperatures owing to the variation in line OD. The rate of the chronometer at different temperathe modulus of elasticity of the steel spring. This variation tures is given by the algebraical sum of the ordinates of is sufficiently great to cause a retardation of five minutes the curves OH (natural variation) and OD (corrective funcin the day in a watch fitted with a steel spring and a mono- tion), that is, by the curve OR. Such is the reason of metallic balance, the temperature of which undergoes a Dent's error, which has been corrected hitherto by adding change from oo to 30° C. The employment in the spring of to the natural corrective function of the balance a term of a nickel-steel the properties of which are represented by great curvature given by an auxiliary system. one of the confluent curves (that is, of an alloy having But the same result would be attained by substituting for Young's modulus a maximum or minimum at the average one of the metals of the double ring another metal or alloy of temperature to which the watches are submitted) will which the increase of expansion is much greater than that of obviate the need of a costly compensation. The com- brass, if that metal is rejected, or much less than that of pensation is, of course, not perfect; the difference between steel, and preferably negative, if the brass is retained. The the form of the curve and a straight line, and still more, the curve of Fig. I offers in this respect numerous possibilities. difficulty of obtaining an alloy passing through a maximum Practical reasons lead one to retain the brass and to or minimum at ordinary temperatures, limit the application associate with it an alloy having an expansion which is a of these springs to ordinary watches, and preclude their retarded function of the temperature. Fig. 9, in which the use in accurate chronometers. But in their own province curve OS belonging to steel has been replaced by ONS they represent a real advance, as they reduce the error of referring to nickel-steel, shows a curve OD that can be an uncompensated watch by 90 per cent., and the cost of rendered symmetrical with regard to OH; the sum OR of watches which were approximately compensated by a rough the curves is then always zero, and the problem has a balance by 6d, in the shilling. The trade watchmaking practical solution. gains as much by direct economy as from an increase in I had established this theory in the year 1899, when 'wo

22,

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of the principal Swiss watchmakers, M. P. Nardin, of 6°, which would bring the maximum on November 17, or Le Locle, and M. P. Ditisheim, of La Chaux de Fonds, ten days earlier than in 1872 and 1885. expressed a wish to make a trial of the new balance. The The Rev. W. F. A. Ellison, of Enniscorthy, Ireland, first attempt gave so perfect a result that the balance has writes me that the most remarkable meteoric shower he not since been modified; its adoption by Swiss watchmakers witnessed in November was furnished by the Andromedids. was very rapid, and to-day it is employed in the majority He was extremely surprised to find the radiant of this stream of their best timepieces. It was with a pocket chronometer very active on November 21. At 7 p.m. he counted 8 fitted with this balance that M. P. Ditisheim beat in 1903 meteors in fifteen seconds, and although this rate was not all records at Kew with a total of 94.9 points, the previous maintained, he continued to observe numerous Andromedids best being 92-7. The compensation was awarded 19.7 until midnight. From 7h. to Sh. 24 were seen, from 8h. to points, the maximum of ideal perfection being 20. The gh. after which the number decreased. Until dark-lined curve of Fig. 10 shows the theoretical variations November 28 meteors continued to fall from this radiant, of a persect chronometer compensated by the usual method ; and many of them were objects of remarkable brilliancy, the curves N, N, and H represent the average results quite equal to the Leonids, but the motions were slower obtained at Neuchatel with two groups comprising in all and the paths shorter. The prevailing colour was pure sixteen chronometers, and at Hamburg with six chrono- white, the trains being greenish. The radiant seemed meters, all made by M. Nardin.

further north than Mr. Ellison expected to find it, the posiIncandescent Lamps and Crookes's Tubes.-In con- tion being at about 21° + 50°. clusion, a few words may be given to an application, less The following are some of the larger meteors recorded scientific in its nature than the preceding, but likely to be by Mr. Ellison :welcomed by all who regret the systematic destruction of

Nov. 21. 8h. 2m. G.M.T. = the world's store of platinum. The curve in Fig. 2 shows

Vega. From a point a little that two nickel-steels of definite composition have an ex

above a Cygni exactly across 8 and about 150 pansion equal to that of glass; but only one of these can

further, directed precisely from Vega. be practically considered, namely, that containing about

8h. 49m. = 6. Low down in west where no stars 45 per cent. of nickel; the alloy which contains 29 per cent.,

could be seen to fix the path, but evidently

Andromedid. at a slightly higher temperature passes the point A of Fig. I and enters the region of high expansion.

21. 9h. 8m.= 4. From 337° +7° to 329o 7o. For a metal to fuse in glass it is indispensable, but in

21. 9h. 16m. = 1. From 354° + 30° to 348° + 18o. sufficient, that it should possess the same expansibility as

26. 7h. 35m. = 8. From 52° +27° to 64° +81o. Duraglass ; fortunately the alloy containing 45 per cent. of nickel

tion 2 sec., vivid flash at end. possesses all the other properties which are necessary, pro

28. Sh. 50m. > 8. From about 215° +50° to 215° +46° vided that it be not unduly oxidised during the softening

Very short path, swift and Aashing. Impossible of the glass. As a matter of fact, several manufacturers of

to fix path accurately. incandescent lamps have adopted, under the name platinite, It seems desirable to inquire whether any other observers this welcome substitute for platinum, thereby economising noticed an abundance of meteors on about November 21, several hundred kilograms of the precious metal. If this and if so whether their paths were directed from the usual economy spreads, a ton of platinum may be saved annually radiant point of the Andromedids. for science and those industries in which its use is indis

W. F. DENNING. pensable.

Conclusions. It is time to conclude this over-long article. The appliwtions which have been described are not the only ones

UNIVERSITY AND EDUCATIONAL which might be predicted or have been attempted with these

INTELLIGENCE. curious alloys, the properties of which for a time seemed so paradoxical that a number of physicists and metallurgists appointed university lecturer in mathematics in the place

Cambridge.—Mr. J. H. Jeans, of Trinity, has been refused to believe in their existence. All the applications of Prof. Macdonald, now of Aberdeen University, which to-day give new resources to science and new

The late Mr. G. T. B. Wigan has bequeathed to the onomies, representing large sums, to industry arise from peculiar phenomenon of equilibrium in the mutual solution

university some goool., the interest of which is to be used of two isomorphous metals; that is one interesting side of

for the purpose of promoting scientific education and rethe question. There is another on which I would insist in

search. It is proposed to divide the fund equally between concluding; it is that these results have been obtained as

the board for physics and chemistry and the board for a sequel to a long series of delicate measurements in which

biology and geology. Each board will administer the inthe thousandth of a millimetre was the ordinary unit, and

come of its moiety subject to the condition that no portion without which no discovery in this domain would have been

is to be applied to one specified purpose for longer than five possible.

CH. ÉD. GUILLAUME.

years at a time.

The name of the late Frank McClean, F.R.S., the founder

of the Isaac Newton studentships in astronomy, and a SHOWER OF ANDROMEDIDS FROM BIELA'S university roll of benefactors.

generous donor to the observatory, has been added to the COMET (?)

Dr. Donald MacAlister, the representative of the uniWHAT certainly appears to have been a well defined versity on the General Medical Council for the last fifteen

shower of Andromedids occurred on November 21 years, has been elected president of the council in succession and following nights to November 28. Yet this display, if to Sir William Turner, K.C.B., principal of Edinburgh 11 really represented the débris of Biela's comet, like the University. meteors seen in November 1872, 1885, 1892, and 1899, was

Mr. F. F. Blackman, of St. John's, has been appointed not true to its time, for no return was to be expected, in reader in botany in the place of Mr. Francis Darwin. ordinary circumstances, until 1905 or 1906. The period is A university lectureship in botany, stipend 100l., is vacant about 6-7 years, and if the shower displayed itself this year by the resignation of Mr. F. F. Blackman, recently it must mean that the swarm has been much disturbed, or appointed reader. Application is to be made to the Vicethat the meteors are rapidly distributing themselves round Chancellor by December 17, the orbit, and will soon form a continuous stream, visible Prof. E. Waymouth Reid, F.R.S., has been approved annually as the earth intersects it in the third week of for the degree of doctor of science. November

Prof. Woodhead has obtained from friends resident in Dr. Schulhof and Prof. Abelman (Astr. Nach., 3516)

or connected with Huddersfield a sum of more than 1600l. pointed out some years ago that a convulsion of the orbit- for the endowment of a Huddersfield lectureship in special notion of the Andromedids would occur in 1901, as Jupiter pathology. The general board proposes that the gifts be xnuld approach the group to within 0.5 of the earth's gratefully accepted by the university, and that the lecturedistance from the sun in March of the year named. The ship be forth with established. effect would be a displacement of the node to the extent of The museums and lecture rooms syndicate reports that the zoological collections have outgrown their present Steel. An exhibition of geographical appliances, apparatus, accommodation, and suggests that a new zoological museum maps, books, &c., will also be held on the days during which should be arranged for on the site recently acquired from the conference meets. Downing College, in the neighbourhood of the new Sedg

From a long list of recent appointments in such journals wick Geological Museum.

as the Physikalische Zeitschrift, l'Enseignement matheA new diploma is proposed in mining engineering for

matique, and similar sources, we extract the following prostudents who have resided nine terms and have attained a prescribed standard in certain subjects of the natural

fessorships, mainly mathematical and physical :-Germany.

Austria, &c.-S. A. Arrhenius (Stockholm) for meteorology sciences and mechanical sciences tripos. The board of geographical studies has published a report

and cosmical physics at Berlin; H. Battermann for submitting regulations for the special examination in geo

astronomy, and directorship of observatory at Königsberg; graphy for the ordinary B.A. degree, and for the diploma

K. Cranz (Stuttgart) at technical college, Charlottenburg, in geography. The range of subjects is comprehensive, and

Berlin ; 0. Eggert (Berlin) for geodesy at technical college,

Danzig ; Dr. Furtwangler for mathematics at agricultural the standard contemplated is obviously high. The regulations are given at length in the University Reporter, pp.

college, Bonn-Poppelsdorf ; Grassmann (Halle) at Giessen ;

L. Hefter (Bonn) at technical college, Aachen; G. Lands. 301-3. Dr. D. MacAlister and the Right Hon. Sir G. D. T. Goldie, K.C.M.G., have been appointed members of the

berg (Heidelberg) extraordinarius for mathematics at

Breslau ; K. Oertel for astronomy at Munich : R. Prant! board. The memoir of Mr. A. Wood, advanced student of

(Hanover) extraordinary at Göttingen; Rohn (Dresden) for Emmanuel College, on the spontaneous ionisation of air

descriptive geometry at Leipzig: C. Runge (Hanover) at in closed vessels, and its causes, has been approved as

Göttingen; K. Schreber at Greifswald ; J. Sommer far qualifying for the certificate of research.

mathematics, technical college, Danzig ; P. Stäckel (Kiel) The Rev. Francis Bashforth, second wrangler 1843,

at technical college, Aachen, to replace Prof. van Marformerly fellow of the college, and distinguished for his

goldt, who is transferred to Danzig ; Vahlen (Königsberg) researches in ballistics, has been elected to an honorary

at Greifswald; Wellenstein (Giessen) extraordinary for

mathematics, Strassburg. France.--Cartan for calculus at fellowship at St. John's College.

Nancy; Cotton for mechanics at Grenoble ; Drach for

mechanics at Poitiers; Lecornu for mechanics at polyLORD REAY will distribute the prizes to the students of the technic college, Paris, in place of the late M. Sarrau; Northampton Institute, Clerkenwell, on December 9. H. Poincaré for astronomy at polytechnic, Paris; Raffy for PROF. HELE-SHAW has accepted the post of principal

analytical geometry, Paris; Jules Tannery for calculus at organiser under the Transvaal Technical Council for one

Paris. Italy.-F. Guardacci (Florence) for geodesyat year, and has in consequence resigned the chair of professor

Bologna; Mich. Rajna for astronomy, and directorship of of engineering at Liverpool.

observatory, Bologna ; in addition, F. Amadeo has been

appointed recognised teacher for history of mathematics at The registrar of the University of Leeds announced, at Naples. America.-G. H. Hallett and C. A. Holden (extraa Mansion House meeting held at York on November 30 ordinary), Pennsylvania; D. N. Lehmer (extraordinary), in support of the university, that 61,8251. has been sub- California ; James MacMahon, Cornell; Robert E. Moritz scribed toward the 100,000l. required to make the necessary for mathematics, Washington; H. L. Rietz (extraordinary), additions to the buildings and to increase the endowment Illinois; J. H. Tanner, Cornell; A. W. Whitney, Cali. of the university, so as to satisfy the financial requirements fornia ; besides the following instructorships in mathe laid down by the Committee of the Privy Council.

matics :-). W. Bradshaw, Michigan; A. B. Coble, BaltiLORD LONDONDERRY will receive a deputation from the more; L. C. Karpinsky, Michigan; E. B. Lytle, Illinois ; Association of Chambers of Commerce of the United C. L. F. Moore, Massachusetts; A. Ranum, Wisconsin : Kingdom on Monday next, when the following resolution F. C. Touton, Illinois. on commercial education will be submitted :-" That in order to retain our industrial positions and to introduce

The annual dinner of the past and present students of the into this country such further industries as may be profit

Queen's Faculty of Medicine in the University of Birming

ham was held on November 29. In proposing the toast of ably developed it is absolutely necessary to establish or

“ The Medical School," Sir F. Treves said :-" It is very acquire public secondary schools of the highest standard,

much to be regretted that very little heed is given to science and to provide sufficient inducements by bursaries, exhibi

in this country. There was a time when the man of science tions, scholarships, or otherwise to make the efficient boys stay long enough to take full advantage of the provisions simply allowed to starve.

-Galileo, for example-was cast into prison ; now he is

There is no kind of encouragemade for higher technical and higher commercial educa

ment offered to science. In every university throughout the tion.”

country the same story is told. I think that those men The third annual meeting of the North of England Educa- who devote themselves to science in this country deserve tion Conference will be held in the St. George's Hall, Liver- rewards infinitely beyond any they have ever received." pool, on January 6 and 7, 1905. The subject to be discussed Mr. Chamberlain, who was present in his capacity of Chanon the first morning is Leaving Certificates." Lord cellor of the university, in proposing the toast of "Students, Stanley of Alderley will preside, and papers will be read Past and Present," referred to the remarks of Sir F. Treves. by Mr. G. Alexander, Mr. Owen Owen, and the Rev. J. B. Mr. Chamberlain said :-"I am afraid that for all time Lancelot. The discussion will be opened by Sir Oliver come probably science, and the conferring of great Lodge and Mr. G. Sharples. In the afternoon of the same benefits upon one's fellow-creatures, must be, to a large day there will be three separate conferences dealing re- extent, its own reward. But the pursuit of research is an spectively with “ Manual Training,” the “ Teaching of impossibility so long as the actual means of existence are Geography,”

and “ Child Study.' Principal Reichel will wanting, and the professional practitioner when he starts read a paper on the first subject, Mr. Mackinder on the is, in very many cases at any rate, so tied by the necessity second subject, and Prof. Sherrington on the third. The of providing an actual subsistence for himself and his family subject for discussion by the conference as a whole on the that anything like original and continuous research is in morning of the second day is “ Scholarships, with Special his case impossible. That can only take place when there Reference to the Coordination of Education.” Sir William are in this country schools established where for a year or Anson will take the chair, and papers will be read by Miss two, perhaps in their younger time, men of ability and of S. A. Burstall and Dr. T. J. Macnamara. Messrs. Gore interest in school subjects can be brought together under and Edwards will open the discussion. In the afternoon capable heads, and can carry out on the most extended scale the conference will be divided into three parts to discuss that series of researches which already, in the hands of some the “ Teaching of Domestic Science, "School Games,

of our most distinguished men of science, have led to such with Special Reference to Day Schools,” and the “ Teach- important results.' During the course of his remarks Mr. ing of English.' Domestic science will be dealt with in Chamberlain also said that three classes of people are essential papers by Miss Fanny Calder and Miss E. Pycroft, school to the success of a modern university-students, teachers, games by Messrs. J. L. Paton and F. W. Augell, and the pious benefactors. Unfortunately," he said, we have teaching of English by Miss E. Drummond and Mr. G. C. fewer pious benefactors in this country than they have in

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the United States of America, where, by their munificent character of the curves expressing the relation between donations, counting by millions, they have covered the land temperature and conductivity in aqueous solutions of the with a net-work of universities which have brought higher alkalies.' The principal results of the investigation are as education within the reach of almost every citizen. I hope follows: the time is coming when men who have more than they (1) In the most dilute solutions, in which " ionisation" want, more, perhaps, than is good for them, can find no is nearly complete, and again in the most concentrated better opportunity of disposing of the surplus than by bene- solutions, the curves expressing the relation between factions which not only are of present usefulness, but, what molecular conductivity and temperature in aqueous solutions is of more importance, are of permanent advantage to the of sodium hydroxide are not inflected between o° C. and community amongst which they live."

100° C. In each case the form of the curve appears to be Os Thursday last, December 1, the prizes and certificates

determined mainly by the rapid changes of viscosity which gained by students of the Sir John Cass Technical Institute

accompany changes of temperatures. Moderately dilute during the session 1903-4 were distributed by Sir William

solutions give curves that are inflected between o° C. and White, K.C.B., F.R.S., when the chair was taken by Sir

100° C.; the temperature of inflection reaches a minimum, at Owen Roberts, chairman of the governing body. Sir

48° C., in the case of a normal (4 per cent.) solution, but William White, in the course of his address, said that

rises to 100° C. when the concentration is raised to 30 per during his recent visit to America he had had the opportunity of studying the methods of technical education in

(2) The inflected conductivity-temperature curves can be vogue there, and he must certainly confess that both

represented by the formula America and Canada can teach us a great deal so far as

ke/Ko=polpo.(1 + bt)" c-at. technical colleges in general, and the interest taken by employers of labour in the future employment of men trained

This formula is applicable to conductivity-temperature curves in technical institutions, is concerned. The essential of all kinds, and gives expression, not only to the inflection advantage which America and Canada, and also Germany, now. under consideration, but also to the maximum conpossess over this country is that they are all imbued with ductivity and the second inflection in the general conthe idea that it is a wise investment on the part of a nation ductivity-temperature curve.? to provide for all kinds of education from the elementary

(3) The maximum conductivity of caustic soda at 18° C. up to the highest. It is almost impossible to make expendi- is 0.3490 in a 15 per cent. solution, the value given by ture on education too lavish, provided it is well directed,

Kohlrausch being 0.3462. At higher temperatures the if the nation is to be well educated. This country, in his

maximum conductivity is considerably greater, rising to opinion, will never reach a truly healthy condition until more than 1.4 at 100° C., and occurs in solutions of greater every man or woman, in whatever position the accident of concentration. birth may place them, shall, if they possess the capabilities,

(4) The viscosity of a 50 per cent. solution of sodium have also the opportunities of self-culture. Nevertheless, hydroxide is approximately seventy times as great as that of there is one respect, he thought, in which this country

water. The influence of this factor may be to some extent stands supreme. It is in the provision of evening classes for eliminated by dividing the molecular conductivity by the the working man and the working woman who, from the

fluidity, and this ratio it is proposed to call the “ intrinsic very nature of their circumstances, are compelled to work conductivity " of the solution. Whilst the molecular conall day to get a living. Employers should assist these ductivity of sodium hydroxide solutions decreases steadily educational classes more than they do at present. The as the concentration is increased, the intrinsic conductivity London and South-Western Railway Company are doing

falls to a minimum at about 8 per cent. NaOH, and then what may well be done by other large employers. They rises, until at 50 per cent. NaOH, the value is considerably grant to the apprentices in their works at Nine Elms the greater than in the most dilute solutions. It is believed necessary time to attend the early morning classes at the

that this increase is due to the fact that liquid soda is an Battersea Polytechnic. The apprentices are allowed to go

electrolyte, per se, and that, in concentrated solutions, the to these classes twice a week, and are paid for the time current is conveyed partly by the soda alone, as if it were that they are away from the company's service, on the

in the fused state. rondition that they do a certain amount of study at home, (5) In re-determining the densities of aqueous solutions thus completing in the evening the training which they of sodium hydroxide, quantities of sodium, amounting to receive during the day at the polytechnic. This is not about 150 grams at a time, were weighed, and converted altogether an experiment. The Admiralty has done the quantitatively into concentrated solutions of sodium sante thing for fifty years or more, with the result that hydroxide by the action of steam in a platinum vessel. the Admiralty, from the apprentices in its own dockyards, Eleven determinations, made with six different standard has trained not only many of its principal shipbuilding solutions, gave, as the density of a 50 per cent. solution officers and naval architects for the Royal dockyards and at 18° C., the value 1.5268, with an average error of 0.0001. the Admiralty service, but has also furnished to the private Solutions of known concentrations having been prepared by shipbuilding industry of the country some of its most dilution, their densities were determined with a probable famous shipbuilders. The leaders and managers in those error of not more than 0.0001; the values recorded by great private establishments to-day are in no small pro- previous observers were derived from solutions standardised portion drawn from men who were trained in the Admiralty by titration only, and appear to contain errors in the third service under the system which has been in operation, and or even in the second place of decimals. by which every apprentice who cares to improve his mind (6) In the formula has the opportunity to do so. If employers will give the

Pe=Po + at + B12 +13, utmost encouragement to institutions like the Sir John (ass Institute, they will be rewarded by having capable

which represents the influence of temperature on the density men on their staff who will know the principles of their

of water and aqueous solutions of soda, the coefficient of 13

vanishes when a concentration of 12 per cent. NaOH is business.

reached, whilst the coefficient of t vanishes at 42 per cent. NaOH ; at the latter concentration there is a simple linear

relationship between density and temperature. SOCIETIES AND ACADEMIES.

(7) The molecular volume of sodium hydroxide in dilute

aqueous solution has a large negative value, a litre of water LONDON.

dissolving 140 grams of sodium hydroxide at o° C., 100 Royal Society, November 17.-" The Electrical Con- grams at 18° C., or 60 grams at 50° C., without inductivity and other Properties of Sodium Hydroxide in creasing in volume. The molecular volume does not inAqueous Solution, as Elucidating the Mechanism of Con- crease continuously as the temperature rises, but reaches a duction." By W. R. Bousfield, K.C., M.P., and T. M. maximum value at about 70° C. In a 50 per cent. solution Lowry, D.Sc.

the temperature has little effect on the molecular volume, The original object of the research was to investigate the extreme variation being only about 10 per cent. the decay, as the temperature rises, in the “ionising

i Compare Roy. Soc. Proc., 1902, vol. Ixxi. pp. 42-54. properties of water, which is manifest in the inflected

2 Loc. cit., p. 52.

Entomological Society, November 16.- Frof. E. B. Biologia Centrali-Americana," and to Mr. Buckton's Poulton, F.R.S., president, in the chair.—Mr. H. St. J. monograph, in which latter work an attempt has been made Donisthorpe exhibited the second recorded British speci- to classify the family so far as at present known. The men of Orchestes sparsus, Fahr., taken by him on August 28 specific descriptions are chiefly founded on specimens from in the New Forest.-Mr. H. W. Andrews exhibited speci- the museums of Madrid and Brussels. Most of the new mens of Atherix crassipes, Mg., from the New Forest, the species are from Mexico and Central America, six from only previously recorded locality in Britain being near Africa, and one each from India, Ceylon, Sumatra, and the Ticehurst, Sussex.—Mr. G. O. Stoper exhibited aberrant Philippines. Mr. Buckton then characterises twenty-four forms of Melitaea athalia from Luan, Switzerland, and new species, five of which are made the types of new genera, Martigny, in which the tendency of the black markings to and the paper concludes with general observations on the supersede the fulvous was particularly noticeable.—The habits, economy, and transformations of the Membracidæ. President exhibited cases containing Diptera, and a case containing the skins of African Sphingid larvæ, dried in

Physical Society, November 25.-Dr. R. T. Glazebrook, botanical paper, and after seventy years still preserving differences of phase : Dr. W. E. Sumpner. Hitherto, in

F.R.S., president, in the chair.-The measurement of small their colours, from the Burchell collection in the . Hope order to measure the differences of phase between alter. Museum, Oxford.-Mr. C. 0. Waterhouse exhibited a gall of some lepidopterous insect found on the califate

nating-current quantities, it has been necessary to use some bushes in Patagonia. The gall resembled that of Cynips

method involving the simultaneous reading of three de kollari, but was hollow, the walls being about inch in

flectional instruments, such as the wattmeter method, or thickness. The circular door prepared by the larva' was

the three-voltmeter method either in its original or in some about } inch in diameter. The pupa was lying free, with

modified form. These methods cannot be successfully out any silk cocoon. It was suggested that the insect was

applied when the phase-differences to be determined are perhaps allied to Ecocecis.-Mr. G. H. Kenrick com

small. The author describes new voltmeter methods which municated a paper entitled “Natural Selection Applied to

may be used for the purpose, and gives the results of a a Concrete Case.”—Mr. J. C. Kershaw communicated

number of measurements on alternating-current plant.papers on enemies of butterflies in south China, and a life

Dr. C. V. Drysdale exhibited and described apparatus for history of Gerydus sinensis.-Mr. Nelson Annandale com

the direct determination of the curvatures of small lenses, municated a paper on the eggs and early stages of a

such as the objectives of microscopes. Parallel light from Coreid bug, probably Dalader acuticosta, with a note on

a distant source falls upon a plane unsilvered mirror inits hymenopterous parasites.

clined at an angle of 45°. Some of the light is reflected and Royal Microscopical Society, November 16.—Sir Ford

brought to a focus by an ordinary convex lens. The surface North, F.R.S., in the chair.-Mr. Hugh C. Ross exhibited

to be tested is placed at this point, and the reflected rays and described a new electric warm stage of his invention.

proceed as if they had come from a point on the surface. Mr. C. L. Curties exhibited two new designs of the Nernst

They pass through the plate glass into a telescope focused

for parallel rays, and an observer sees an image of the lamp suitable for use with a current of 100 and 200 volts

distant source. If the surface is convex and is brought respectively, adapted for use with the microscope, and fitted

nearer to the lens, then, when it reaches such a position with ground glass or blue glass fronts and mounted so as

that its centre of curvature is at the focus of the rays to be used at any height or angle required.-A paper on

emerging from the lens, the light will again retrace its theories of microscopic vision, a vindication of the Abbe

former path and a distinct image of the source will be seen theory, which contained some new views on the subject, was read by Mr. Conrady.

in the telescope. In order to obtain the two images the

surface has therefore been moved through a distance equal Linnean Society, November 17.-Prof. W. A. IIerdman, to its radius of curvature. If the surface is concave it must F.R.S., president, in the chair.-Mr. H. E. H. Smedley

be moved away from the lens. Dr. Drysdale showed how exhibited forty-one models of Palæozoic seeds and cones.

the method could be carried out by means of an auxiliary The models

of the seeds show the complexity of their internal piece fitted to an ordinary microscope. He also described structure, whilst the models of the synthetically re-con

a method of testing the spherical and chromatic aberration structed calamitean and other cones display the high of microscopic objectives. Light from a distant point is organisation of the vascular cryptogams of Palæozoic times. partially reflected by means of a piece of plate-glass down -Note on the shape of the stems of plants : Lord Avebury, the axis of the microscope. In passing out of the objective The author pointed out that while most plants had round it is brought to a focus upon a mirror, and retraces its path stems, in some they were triangular, some quadrangular, along the axis of the instrument until it reaches the plate &c., but that, so far as he knew, no attempt had been made

glass. This it passes through, and by means of a telescope to explain these differences. He thought they could, how- an observer can view the distant source. The light having ever, be accounted for on mechanical principles. In build- passed twice through the lens to be investigated, the effects ing, when the main object was to meet a strain in one of chromatic and spherical aberration are doubled, and at direction, the well known girder was the most economical the same time the effect of coma is eliminated.-Prof. S. P. disposition of material. In a tree-stem it was necessary to Thompson gave an exhibition of specimens of crystals resist strain coming from all directions, and the woody showing the phenomenon of luminous rings. He said it tissues acted as a circular series of girders. In herbs with was well known that when a source of light was viewed opposite leaves the strains were mainly in two directions, through certain samples of calc-spar the field of vision code and were met by two opposite girders, thus giving the tained two luminous rings each of which passed through quadrangular stem. Taking our native flora he showed that

the image of the luminous point. The subject had been all herbs with quadrangular stems had opposite leaves, and

investigated by Dr. Johnstone Stoney, who had attributed as a rule herbs with opposite leaves had quadrangular stems.

the phenomenon to a minute tubular structure in the crystal. Sedges had triangular stems and grasses round stems, and There were, however, certain crystals which when cut in while sedges had the leaves in threes, those of grasses were the ordinary way across the axis and used to view a distant distichous. Pentagonal stems might be accounted for in a source of light exhibited a single luminous ring passing similar way, and incidentally this threw light on the petals through the image of the source. Looking down the axis of so many flowers. Thus plants had adopted, millions of

of the crystals no ring is visible, but on tilting it a ring years ago, principles of construction which have gradually can be seen in the direction of the tilt which grows in been worked out by the skill and science of our architects diameter as the tilt is increased. So far as he knew, no and engineers.-Observations on some undescribed or little

explanation of these phenomena had been offered. At the known species of Hemiptera Homoptera of the family meeting a piece of calc-spar showing the two rings, and Membracidæ : G. Bowdler Buckton. Prof. Poulton has pieces of beryl and tourmaline showing the single ring explained the significance of the strange forms of some of were exhibited. the Membracidæ by their dependence on environment, and

EDINBURGH. the requirements of mimicry; and the Rev. Canon Fowler Royal Society, November 7.-Lord M'Laren in the has also given information respecting the economics of chair.-In a paper on Prof. Seeliger's theory of temporary the species, and their maintenance during the struggle for stars, Dr. J. Halm gave some important extensions bear. life. The present paper may be regarded as supplementary | ing especially upon the characteristics of Nova Aurigæ (1803) to Canon Fowler's work on the Membracidæ in the and Nova Persei (1902). Seeliger's theory, broadly stated,

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