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the same species, the widely different results are probably due was far less severe, it originated within a mile or so of the to the trees furnishing the timber having been grown under present one's centrum, as proven by a knot of submarine cable different conditions. Mr. Mackenzie mentions a curious fact having been then lost, buried under the immense mass wbich “observed in the working of the various pine timbers I have fell into it, at the bottom of the sea ; and by the measurements named. It was found that the wood of pines having three leaves taken at the time. in a sheath was, as a rule, much harder than those having only “This earthquake had precisely the same characteristics as two, whilst all those having five leaves in a sheath were uniformly the present one, both previously and subsequently to its occursoft, and when dressed had a silky appearance. So general is rence, and although very many severe and slight shocks have this characteristic that one could almost at once tell to what been selt since 1873, in no case were they of so pronounced a class a certain plank of pine timber belonged." These observa- local nature as those just recently experienced. When the great tions we do not remember to have seen previously recorded. earthquake of August 27, 1886, occurred, which destroyed

“ The Diseases of Conifers.” Although in German there is a Filialia on the mainland to the south-east of Zante, this island literature of considerable extent on this subject, the publications was fortunately outside the direct vibrative waves of seismic in English are few. Prof. Marshall Ward is a very careful and forces radiating from the centrum of that shock; which covered competent observer, and his contribution to the report is of great up six knots of submarine cable in latitude 37°25', longitude value both to the man of science and to the practical forester. 21°11' east of Greenwich ; but still it did considerable damage,

Mr. W. F. H. Blandford's insects injurious to conisers ar.d its force was severe enough to cause the greatest alarm even is an excellent résumé of all that is known up to date of the life in so distant a place as Malta. history of the various insect pests, which have been noted as “From that year until the spring of 1890 there were numbers injurious to conisers. How important this subject is may be of small shocks, but alter then and up to August, 1892, only a judged by the destruction wrought by the larvæ of Liparus very few tremors were recorded. On August 16 last year about monacha between 1853 and 1868 in East Prussia, Poland, and twelve small shocks suddenly occurred during the day, purely Russia, where the spruce was killed over an area of 7000 square local, and all from east to west. After three days of absolute German miles. A similar instance is that afforded in 1890 in tranquillity they began again, and although merely pulsations the Bavarian forests by the same destructive insect, the loss they were of a very pronounced character. caused by this to the revenue being estimated at £40,000. " At midnight on August 27 the shock was strong, and from Those, however, who, like the writer of these notes, travelled then until the still smarler shocks of September 3 and 5 the over the districts affected during the ravages of the larvæ, would earth seemed always shaking. Another few days of quiescence realise much more vividly the gravity of the attack than others were followed by a renewal of shocks. This state of things could from a mere perusal of statistics.

continued until the middle of January last-and was agaio Not the least valuable portions of the report are the stat- succeeded by a fortnight of perfect tranquillity. At 9 p.m. on istics of conifers in the British Islands, and the value in January 30'a very distinct rumbling occurred, which was folthe British Islands of introduced conisers, by Mr. Malcolm lowed by a short, sharp shock, as if from some falling mass, Dunn. These statistics representan enormous amount of and then all was still again. I noticed after the shock a series energy and perseverance on the part of the compiler. The tabu- of small ripples on the sea, which was previously and lated forms give particulars from a large number of places in the subsequently quite calm. The night passed very quietly until British Islands, and deal with the soil, altitude, age of trees, 5.34 a.m., local time, when the whole island began to sway their height, girth, &c. The list of conifers and largest terrifically from east to west, with a purely undulating motion, specimens, also by Mr. Dunn, gives the dimensions of the

finishing up by a movement which I can only describe as largest specimens taken from the above mentioned tables and being similar io that of some mighty force wrenching out the also the number of returns respecting each species. G. N. bowels of the earth. This shock lasted twelve seconds, and

its centre was undoubtedly in the sea very close to the town,

and due east of the same. From its apex of origin its range THE EARTHQUAKES IN ZANTE.

of destruction, on the frontage of the town, was not wider than

two miles, spreading out to about fifteen when it reached the LAST week we noted the fact that another disastrous earth.

villages at the base of the range of hills, six miles off. quake had occurred in Zante on Monday, April 17, and

“ The destructive force had a tendency to incline from that it had been followed by various slighter shocks. Accord. due

to the north-west of the island, which is ing to a special correspondent of the Times at the town of

about 27 miles in length by an average breadth of eigbt, Zante, the centre of the disturbance seems to have been under

a subsequent shock taking a much lower range. During the sea about two miles from land. Before the great shock the inhabitants of the district of Vasilikos, near this centre,

the whole day shocks were alarmingly frequent and numbered

some hundreds between the first and nightfall when everybody heard submarine rumblings, which increased in loudness till the

went to the open ground in a most panicstricken condition. At earthquake occurred. Two huge boulders were detached from

1.56 a.m. on February I another terrific shock took place-not the neighbouring mountain and rolled into the valley beneatb.

so severe as the first, but with a range towards the south-west and The same correspondent records that on the afternoon of April

of increasing destructive force. This shock lasted 20 seconds 21 there were scveral violent shocks.

and was also succeeded by numberless others. After 23 hours The conditions under which this series of earthquakes has

a third severe shock occurred and periodicaily during the whole occurred will no doubt be carefully studied. Meanwhile we may

week others of decreasing intensity took place. Since the first call attention to a good article contributed to the Mediterranean

shock until the present date, at least one thousand (including Naturalist for April by Mr. W. G. Forster, seismologist, pulsations and tremors) have been selt. manager, and electrician, Eastern Telegraph, Zante, on the

“Of course the direct and indirect damage has been very earthquakes which did so much damage in January. From this

great owing to the extensive zone of destruction, the scattered paper we reprint the following historic statement :

nature of the villages and to the bad construction of the houses “From the traditions of the place it has always been considered in general and to their dilapidated condition owing to extreme pretty certain that Zante must invariably expect a more or less poverty of the island. At least half a million sterling is te severe earthquake about every thirty years. I find, however, that quired to rebuild the place, and as this amount can never be this cycle of seismic disturbances common to all earthquake realised many of the ruins are likely to remain untouched and districts in south-eastern Europe and Asia Minor, and that there most of the population will have to emigrate.' exists also a fairly proven and established law which governs these periods of visitation, for instance, whenever any long time has elapsed without the slight shocks-which average one or

SCIENTIFIC SERIALS. more a week in earthquake districts of non-volcanic regions, American Journal of Mathematics, vol. xv. 1 (Baltimore and when to these periods of comparative quiescence succeeds Johns Hopkins Press, January, 1893). — The pièce de résistance one of constant earth tremors, then a disastrous shock is nearly of this number is a memoir by Prof. Cayley on symmetric certain to take place. This is a very important point, and can- functions and seminvariants (pp. 1-74), in which the subor not be neglected when the question as to the origin of the shocks further develops the theory of seminvariants, and in connections is under consideration.

therewith is led to some investigations on symmetric functions * The last strong local earthquake previous to the present The subject is treated with characteristic ability and atiorcs series of shocks occurred on October 26, 1873, and although it ample evidence of the writer's recovery from his recent serious

east

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illness. Prof. Cayley also contributes some tables of pure

1. Greenwich Temperature. reciprocants to the weight S (pp. 75-77). Two short notes

The examination of the tables shows that, with very consider: follow on the differential equation, Au+k?u=0 by Maxime

able variations of absolute magnitude, there is on the whole Böcher (pp. 78-83), and geometrical illustrations of some

very marked consistency in the main characteristics of the theorems in number by Ellery W. Davis (pp. 84-90, with a

components. diagram). M. Halphen is the mathematician whose portrait is

Taking as a test the position of the epoch of maximum, which given with this opening number.

is more directly dependent on the sun's action and on his posiBulletin de l'Académie Royale de Belgique, No. 3 (1893).- tion than the amplitude, it will be seen that the values of u Among the scientific papers communicated to the Acadenyare the indicate very clearly the closeness of this connexion. following: On the common cause of surface tension and evapor. In all the components a truly periodical variation of the value ation of liquids, by G. Van der Mensbrugghe. The author of u is apparent, and the period of maximum always travels deduces from his theory an explanation of the fact that evapor- backwards, that is, it becomes earlier as the year passes from alion is more rapid from a convex, and less rapid from a con- winter to summer, while it returns in the opposite direction in cave, than from a plane surface.-Survival after the successive the change back to winter. section of the two vagi, by M. C. Vanlair. Survival after For the first component the variation of the five years' mean successive section of both the branches of the vagus nerve can of u from the twenty years is in no month more than 2, or ten be obtained in sull-grown animals as well as in young ones. minutes of time, and the average for all months is less than half The time necessary for the regeneration of its inserior laryngean that amount. branch is generally much longer than that hitherto accepted. In the second component the variation of the five-year mean In the full-grown dog the period exceeds at least ten months. from the twenty-year mean is in no month more than 6°, and The regeneration of one branch is quite independent of the the average is only 2°-3, or nine minutes of time. section of the other. The question whether the pneumogastric, In the third component the variation of the five-year from the like the sciatic nerve, possesses the power of regenerating itself twenty-year mean in no month exceeds 5', and the average in tuice in succession remains as yet unanswered. It is, however, all months is only 20 :1, or 8 minutes of time. certain that an interval of six months and a half does not suffice The largest variation of the five-year mean of the fourth comfor its second regeneration.-On the digestion of the coelen ponent for any month from the twenty year mean is 10°, and the terata, by Marcelin Chapeaux. The action of the serments average for all months is 4°:3, or seventeen minutes. Considersecreled by the actinia upon starch, cellulose, chlorophyll, and ing huw small are the absolute values of the coefficients Pa and fat, was investigated. Starch submitted to the action of an 94, on which the value of us depends, the average being a little aqueous solution of these ferments, or injected into the gastro- less than oth of a degree Fahrenheit, it is rather a matter of vascular cavity, was transformed into glucose. The action was surprise that the variations should be so small than that ihey slow in the case of non-hydrated starch. The transformation should reach their actual amounts, took place equally well in acid and in alkaline solutions. The component of the first order, which in the winter is more Cellulose and chlorophyll were not digested. The fats were than double the magnitude of any of the others, and in summer emulsioned by the ferments contained in the endodermic more than ten times as great, gives the dominant character to cellules. These ferments were without effect upon the algæ. the daily curves of temperature. In the series of twenty years Among the Siphonophora digestion is certainly exclusively variations in different years of as much as 100 per cent. are to be intracellular. No dissociation of fibrine is, on the other hand, found for almost every month, but sor the most part even these ever observed in the gastrovascular cavity, and no difference irregularities disappear in the mean of a series of five years, could be established between the alkalinity of the liquid con. and the monthly means for the twenty years are remarkably tained in this cavily and the surrounding sea-water. -Contri. consistent. bution to the nitrogen question, by A. Petermann. This is an The progression of the value of P, in the course of the year, experimental confirmation of the results of MM. Schlæsing fils follows approximately the sine of the sun's meridional altitude and Laurent, showing that free nitrogen is absorbed from the air and the empirical formula by the micro-organisms of the soil.

P = 10 COS % - 091

gives a close approximation to the values shown in the tables, if SOCIETIES AND ACADEMIES.

a "lagging” of eight or ten days is allowed in reckoning the

sun's place. LONDON.

The second component has two clearly marked maxima about Royal Society, March 2.—“Harmonic Analysis of Hourly the time of the equinoxes, and a principal minimum at midObservations of Air Temperature and Pressure_at_British Observatories,” by Lieut.-General R. Sırachey, R.E., F.R.S. The component of the third order varies in a converse

This paper is a discussion of the resulis of the compu'ations manner, having two well-marked minima at the equinoxes, with contained in a volume recently published by the Meteorological a principal maximum at midsummer. Office of the harmonic components of the first four orders, for each The component of the fourth order appears to combine the month for twenty years, of the daily curves of temperature and characters of the two previous ones, having two maxima about pressure at Greenwich ; and for ihe first three orders, for the the time of the equinoxes, and a principal minimuin in the temperature and pressure, for each month for twelve years, at winter. the seven observatories maintained by the Meteorological The mean value of u for the first component is 214°, correOffice.

sponding to 2h. 26m. p.m., the variation due to season being This system of analysis supplies the means of establishing an 12° or 48m, of time, by which the maximum is earlier in summer exact comparison between various unsymmetrical curves, such as than in winter. those representing hourly values of temperature, by resolving In the second order the first maximum in June is 24°, or ih. them into symmetrical components, having periods of twenty- 20m. earlier than in January. four hours, twelve hours, eighi hours, and six hours, and so In the third order the difference in the same direction is 63°, forth, and its application to the records dealt with in the tables or 4h. 12m. of time. contained in the volume above referred to gives satisfactory In the fourth order there is some doubt as to the manner in proof of the important light it can bring to bear on the periodical which the change of epoch of the summer and winter maxima is changes of diurnal temperature.

brought about. But remembering that the fourth component in In the usual expression the coefficients of the cosines of the cludes four series of undulations, the most probable explanation of arcs are designated by the letter p, and those of the sines by 9. these changes is to be found in a change of the position of these The total amplitude of the component is designated by P. undulati, ns, during which, between January and February, when

A modification of the usual notation is made by the introduc. the first maximum is about 10° aster midnight, or oh. 40m. a.m., tion of the value of the epoch of the first maximum that occurs the first recedes, and its place is taken by ihe second, which after midnight, which is designated by the letter H, and estab. leads to sudden appearance of a maximum about 60°, or 4 a.m. lishes the connexion of the component with the hour of the day A similar change between October and November in an and the sun's place more conveniently than the method usually opposite direction would reproduce the maximum at 10° after adopted

midnight.

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In the summer months (May, June, and July) the temperature lowest values being those for Valencia and Falmouth, no doubt curve during the day hours, from 8 a.m. to 8 p.m., hardly due to their position on the sea coast, for wbich stations the differs from a curve of sines, the first component being more means for the years are 2° -28 and 29:35 compared with 5*10 than ten times as large as any of the others, which therefore at Greenwich. influence the temperature, relatively, very little.

The Kew values most resemble those at Greenwich, but the The relation of the epoch of the first maximum of the com- mean maximum at Kew is more than ro less, and the mean for ponent of the third order to the time of sunrise is decidedly the year less. marked, the former occurring, on the average, about 12°, or The mean values of my for the seven observatories lie be48m. after sunrise ; the mean deviation of the interval from that tween 205' and 220", that for Greenwich being 214" The amount being only 7°, or 28ın.

means of tbe summer values are about 3 or 4 less than the The periodical variation in the position of the maximum leads, mean of the year, and of the winter values as much above it. during ihe winter months, to a positive maximum of this com- as in the case of Greenwich. ponent about i p.m., which is combined with negative maxima The amplitude of the first component conforms approxi. four hours earlier and later, which correspond to the nduced mately, but not so closely as at Greenwich, with the sine of temperature in the mornings and afternoons of the shorter days. the sun's meridian altitude, but with a fattening of the curve In like manner, in the summer months, when this component in the summer months, and a tendency at some of the stations has a negative marimum about i p.m., instead of a negative to a maximum value in Vay. minimum, as in winter, there will be two positive maxima, one The components of the second and third orders, teyond which four hours earlier, the other four hours later, corresponding to the the analyis is not carried for these observatories, conform in all higher temperature in the mornings and afternoons of the longer | important respects to those for Greenwich, the numerical valdays.

ues of the latier being, however, in all cases somewhat higher. It will be seen that these positions of the midsummer and mid. The epochs of maximum follow the same laws, with an increased winter maximum phases correspond respectively to days of 16 divergence of the summer epoch from that of the winter at the hours with nights of 8 hours, or days of 8 hours and nights of more northern stations. 16 hours, and that at these seasons, when the variations of tem- In order to test, and in some degree throw light, on the charperature, due to these differences, are greatest, the amplitudes of acter and significance of the harmonic components of temperature this component are also the greatest. At the equinoxes, with that have been under discussion, and bearing in mind that they 12-hour days and nights, the component becomes a minimum ; cannot be considered to represent separate effects of physical and at this season the change in the position of the maximum forces operating at the assumed periods of the components, I takes place as already noticed.

have, at the suggestion of Prof. G. Darwin, calculated the It might be supposed that an analogous relation between the harmonic components from a curve representing an intermitteri fourth component and the occurrence of days of 18 hours, com- heating action such as that of the sun, continued only during 2 bined with nights of 6 hours, and vice versii, is likely to arise. portion of the day, and commencing and ending abruptly at But the data are not forthcoming to test this.

sunrise and sunset. In the summer months the time of mean temperature is nearly All cooling effects have been disregarded, and the sun's direct where the first component becomes zero, the second and third | heating action is assumed to be proportional to the sine of his components then balancing one another.

altitude, the power of a vertical sun being taken to he io. HasIn the winter the time of morving mean temperature is later ing calculated the sun's altitude for each hour of the day, for than in summer, and occurs when a positive value of the first midwinter, the equinox, and midsummer, for certain selected component is equal to a negative value of the second.

latitudes, the corresponding heating effects have been computed The time of afternoon mean temperature throughout the year to which the usual method of analysis has been applied. is somewhat either before or after 7 p.m., and almost exactly The comparison of the results thus obtained with the corte coincides with the time when the first and second components sponding components derived from actual observation a: places are equal, with opposite signs.

having nearly the same latitudes as those selected, establishes In the summer the time of absolute minimum is between the their close similarity, and the conclusion is unavoidable, that, hours of 3 a.m. and 6 a.m., during which the whole of the although both in the actual and hypothetical cases the harmonicomponents are negative.

components when combined are truly representative of the pecaSunrise in December is about an hour and a half before the liar forms of the curves from which they were derived, this atfords time of mean temperature ; while in June it is more than four no evidence of the existence of recurring cycles of action corhours earlier.

responding to the different components, but that the results are, Sunset in December is rather more than three hours before the to a great extent, due to the form of the analysis. time of mean temperature ; in June it is about half an hour after The diurnal curve of temperature is not symmetrical in relathat time.

tion to the mean value, the maximum day temperature being The rationale of some of the empirical rules for obtaining the much more in excess than the minimum night temperature is it mean daily temperature from a limited number of observations defect. To adjust the first component, which is symmetrical is supplied by reference to the harmonic expressions for the about its mean value, to the actual unsymmetrical curve, it hourly deviations of temperature from the mean value.

inust be modified by the other components. That of the second In the first place, it will be seen that by adding together the order, which has one of its maxima not far removed from the harmonic expressions for any two hours twelve hours apart, the minimum of the first order, supplies the chief portion of the whole of the odd components di-appear, and that the sum is compensation due to this cause. twice the mean value, added to twice the sum of the even com- Further, from the character of the analysis, when the diarna ponents of the selected hours, which are equal.

curve is symmetrical on either side of the hour half way between By taking the mean of observations at any four hours, at noon and midnight-that is, when the day and night are equal intervals of six hours, both the odd components and those of in length-the third component becomes zero. Any departure the second order will disappear, and the result will only differ from this symmetry introduces a component of the third order, from the true mean by the amount of the fourth component for with the result that with a day shorter than 12 hours one max. the selected hours.

mum will fall in the day between 6 am. and 6 p.m., and the So, if the mean of any three hours at equal intervals of eight other two in the night lietween 6 p.m. and 6 a.m. ; while with hours be taken, the sums of the first, second, and fourth com. a day longer than 12 hours, two maxima will occur in the day ponents will disappear, and the result will only differ from the and only one in the night. In the former case the negative postrue mean by the amount of the third component for the selected tions of the component correspond with the reduced morning hours, which in no case can be so much as 1 :

and afternoon temperatures of the short day, and in the latte

the two positive phases correspond with the higher temperature 2. Temperature at the Seen Observatories.

of the mornings and afternoons of the longer day.

These conclusions are in conformity with those previous's The examination of the tables will show that in their main indicated. characteristics the results closely resemble those for Greenwich, The available data are insufficient to enable us to say whether and it will not be necessary to discuss them in any detail. the corresponding results connected with the fourth component

The amplitude of the component of the first order is, how- are as fully supported by observation as in the case of the third, ever, in all cases less than that observed at Greenwich, the but the facts so far as they go confirm this view.

a

Anthropological Institute, April 11.-Prof. A. Macalister, nodular limestone-bands.—This paper gave rise to a discussion President, in the chair. -Mr. G. M. Atkinson exbibited a in which the President, Prof. Hull, Mr. Walford, Prof. Judd, cranium and several metal ornaments found by Mr. A. Michell General McMahon, Prof. T. R. Jones, Prof. Hughes, Mr. H. Whitley and Dr. Talfourd Jones in a grave at Birling, near W. Monckton, Dr. G. H. Hinde, and the author took part. Eastbourne, Sussex. The peculiar coffin-like shape of the skull On some Bryozoa from the Inferior Oolite of Shipton Gorge, seemed to point to its belonging to the early Saxon period, Dorset, Part II., by Edwin A. Walford. while the metal ornaments were assigned to the late Roman or

Royal Meteorological Society, April 19. - Dr. C. Theoimmerliately post-Roman age. -Mr. R. Duckworth read a paper

dore Williams, President, in the chair. —The following papers on two skulls from Nagyr, recently added to the Cambridge

were read :- The direction of the wind over the British Isles, University collection. One of them is a female skull, and is remarkably dolichocephalic, the cephalic index being 69:94.

1876-80, by Mr. F. C. Bayard. This is a reduction on an The other skull is that of an adult male.-Prof. Macalister read

unisorm plan of the observations made twice a day, mostly at a paper on Egyptian mummies. He described the manner in

9 a.m. and 9 p.m., at seventy stations during the lustrum 1876– which they were prepared, the unguents used by the Egyptians

80 ; and the results are given in tables of monthly and yearly and the various cloths in which the mummies were rolled.

percentages.- Notes on two photographs of lightning taken at

Sydney Observatory, He explained the difference between the Egyptian cloths and

December 7, 1892, by Mr. H. C. those manufactured in England at the present day, and said that

Russell, F.R.S. These photographs were taken with a halfthe object of using so few threads in the weaving was for the pur

plate view lens, mounted in a whole plate camera, and, as a pose of saving time and trouble. The material at the same time

matter of course, there is some distortion at the edges. Both was brought to a high state of perfection as a manufacture, and

photographs show the gaslights in the streets as white specks, indeed might even compare with some of the finest linen pro

the specks being circular in the centre and crescent-shaped in ductions at the present day. Specimens of cloth were exhibited

other parts of the plate owing to distortion. The lightning

flashes are also distorted. Mr. Russell believes that this distorand the author stated, on the authority of a linen manufacturer, that there was only one specimen of linen manufacture in the

tion may account for the so-called “ribbon ” flashes, which are United Kingdom which could be recognised as of similar

seen in many photographs of lighıning. He has also made some

measurements of the length and distance of the flashes, and of structure to the Egyptian productions.-A paper on Damma Island and its natives by P. W. Bassett Smith, R.N., was also

the intensity of the light. -Notes on lightning discharges in the read.

neighbourhood of Bristol, 1892, by Dr. E. H. Cook. The

author gives some particulars concerning two trees in Tyntesfield Geological Society, April 12.-W. H. Hudleston, F.R.S., Park, which were struck by lightning, one on June 1 and the President, in the chair. — The following communications were other on July 18, and also some notes concerning a fagstaff on read :-On soine Palæozoic Ostracoda from Westmoreland, by the summit of Brandon Hill, which was struck on October 6.Prof. T. Rupert Jones, F.R.S. In 1865 the author determined Constructive errors in some hygrometers, by Mr. W. W. for Prof. Harkness some fossil Ostracoda which he had obtained Midgley. The author, in making an investigation into the from the Lower Silurian rocks of South East Cumberland and hygrometrical condition of a number of cotton mills in the Bolton North-East Westmoreland, and subsequently other specimens district, found that the mounting of the thermometers and the mentioned by Harkness and Nicholson in 1872. In 1891 Prof. position of the water receptacle did not by any means conform Nicholson and Mr. Marr submitted a series of similar microzoa to the regulations of the Royal Meteorological Society, and were from the same district; and the author now endeavours to de- so arranged that they gave the humidity results much too high. termine their specific alliances, and revises the list of those pre- The Cotton Factories Act of 1889 prescribes the maximum viously collected. He has to notice about eleven forms of weight of vapour per cubic foot of air at certain temperatures ; Primitia, Beyrichia, Ulrichia, Æchmina, and Cytherella---several and the author points out that if the instruments for determining of them being closely allied as varieties, but all worthy of study the amount present in the mills have an error of 20 per cent. as biological groups, such as have been illustrated from other against the interests of the manufacturer, it is necessary that the regions by writers on the Ostracoda, with the view of the exact makers of the mill hygrometers should adopt the Royal Meteordetermination, if possible, of species and genera, of their local and ological Society's pattern for the purpose. more distant or regional distribution, and of their range in time. -On some Palæozoic Ostracoda from the Girvan district in

PARIS. Ayrshire, by Prof. T. Rupert Jones, F.R.S. This paper aims Academy of Sciences, April 17.-M. Lowy in the chair. at the completion of the palæontological account of the Girvan -Note on the observation of the partial eclipse of the sun of district, so far as the Ostracoda are concerned ; and follows up

1;

April 16, 1893, by M. F. Tisserand. - On the observation the researches indicated in the “Monograph of the Silurian of the total eclipse of the 16th inst., by M. J. Janssen. — Fossils of the Girvan District in Ayrshire," by Nicholson and Effects of the drought upon this year's crops ; reply to Etheridge, vol. i., 1880. In about a dozen pieces of the fossili. M. Demontzey's note on the planting of the highlands, ferous shales, submitted for examination some few years ago,

by M.

Chambrelent. —Expansion of water the writer finds nearly thirty specimens of Primitia, Beyrichia, pressure and at constant volume, by M. E. H. Amagat. At Ulrichia, Sulcuna, and Cypridina which show interesting pressures higher than 200 atmospheres water has no maximum gradations of form, not always easy to be defined as specific or density above zero. At the lower temperatures, contrary to even varietal, but valuable as illustrating modifications during what takes place in the case of other liquids, the coefficient of the life-history of individuals, thus often leading to permanent expansion increases with the pressure. This increase is grad. characteristics of species and genera. Like those formerly de. \ ually effaced as the temperature rises, is sensibly zero at 50° or scribed in Nicholson and Etheridge's “Monograph,' the 60°, and changes sign for higher temperatures. If water is kept specimens have all been collected by Mrs. Elizabeth Gray, of at a constant volume the pressure increases rapidly with the temEdinburgh.—The reading of these papers was followed by a perature. Thus, for unit volume the coefficient of pressure discussion, in which the President, Mr. Marr, and the author increases fourfold between 10° and 100°, and the variation is took part. -On the dwindling and disappearance of limestones, proportionately even more rapid between oo and 10°:-On the by Frank Rutley. The existence of chert between two sheets structure of simple finite and continued groups, by M. Cartan. of eruptive rocks at Mullion I-land seemed to the author to re- -On a simple group with fourteen parameters, by M. F. quire some explanation. Cherts are usually associated with Engel. -Demonstration of the transcendental nature of the limestones, and the absence of limestones in many cases where number e, by M. Adolf Hurwitz. -Comparison of the intercherts are sound points to their removal by underground waters. national meter with the wave-length of cadmium light, by M. The older the limestone the greater the probability of its thick. Albert A. Michelson.--Photography of gratings engraved upon ness having dwindled. The thicknesses of the Ordovician, | metal, by M. Izarn. It is possible to reproduce opaque gratSilurian, Devonian, and Carbouiferous Limestones seem to be ings engraved upon metal in a manner analogous to the reproin the ratio of 1:15:15: 100. Many limestones once existing duction of transparent ones already described. On covering in Archæan rocks may have disappeared, as also limestones in such a grating with a layer of bichromated gelatine, and expos. later rocks. The author comments on the difficulty of distin- ing to the sun through this layer, a grating effect is produced guishing some cherty rocks from felstones. Two appendices are which, although rather feeble, is due to successive differences of added to the paper, the first on the tra sference of lime from structure corresponding to the rulings. These differences of older to newer deposits, and the second on the formation of structure are probably due to stationary reflected waves, and

at

constant

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