Slike strani

German females, all cultivated plants, were crossed with wild Danish males, and the 744 resulting seedlings were investigated. Despite the fact that the wild males were presumably poor in lupulin, offspring variants having a higher lupulin percentage than the mother plant were produced. Improvement in this direction of higher lupulin content has thus been established, since the richest plants can be vegetatively propagated.

A PAPER of some interest on "The Influence of Temperature and Certain Other Factors upon the Rate of Development of the Eggs of Fishes," by A. C. Johansen and A. Krogh, has been published by the International Council for the Study of the Sea, as Publication de Circonstance, No. 68. By means of a specially designed thermostat the authors have kept the eggs of plaice and of cod at a series of different temperatures, and have recorded the time taken until the larva has reached a certain definite length. The main conclusion arrived at agrees with that reached previously by Dannevig, who had worked with less refined methods, namely, that the increase in rate of development with the temperature is proportional to the increase in temperature, or the curve expressing the relation between temperature and rate is a straight line. The authors have also studied the influence of low oxygen pressure upon the development of the eggs of plaice.

CAPT. S. A. WHITE, the President of the Australian Ornithologists' Union, is to be congratulated in having re-discovered a long-lost bird. This is the chestnut-breasted whiteface (Aphelocephala pectoralis), described originally from a single specimen by the late John Gould in 1871. Since then, all search for further specimens has proved unavailing, until Capt. White found it again, in small flocks, during an expedition to the Everard and Musgrave Ranges. Judging from the plumage of immature birds which he secured, he believes that this species interbreeds with the black-banded whiteface, which is highly probable, since the two species were often found in company. Capt. White gives an interesting account of his travels in the Emu for April. A camel-train furnished his means of transport, but throughout no small inconvenience was suffered by all the members of the expedition, including the camels, by reason of the prolonged drought, which, save for occasional and isolated showers, has now lasted for nine years in this region.

AN interesting article on the fur-bearing mammals of California, by Mr. H. C. Bryant, the game expert to the California Fish and Game Commission, appears in the April number of the new periodical, California Fish and Game. In a survey which dates back to 1786 the author traces the history of the ruthless and wasteful destruction of fur-bearing animals which has gone on without check until the present day. As a result some of the most valuable animals have been exterminated, while others are on the verge of extinction, a fate which can be averted only by instant and vigorous protective legislation. Among these is the sea-otter, which less than a hundred years ago

was taken by the thousand; to-day no more than a few pairs are left. Some idea of the magnitude of the slaughter which is taking place may be gathered from the records of the total "catch" of last year in North America. This includes musk-rats 15,000,000, opossums 2,800,000, raccoons 2,400,000, skunks 2,152,000, minks 630,000, and "civet cats" (Bassaris) 500,000. To these must be added foxes, wolves, bears, otters, wolverines, pumas, wild cats, and martens, to the number of 1,500,000. Unhappily, the increased. demand for furs is accompanied by a serious diminution in the area inhabited by the victims, owing to drainage and the destruction of forests. It is devoutly to be hoped that this appalling rate of destruction may be checked, at least, by the efforts which are being made to breed silver foxes and skunks for the sake of their skins. A number of "fur-farms" are already in a flourishing state, but so far their output is not sufficient to diminish materially the toll' levied on the wild animals.

[ocr errors]

THE acid secreted by the gram plant, Cicer arietinum, forms the subject of Bulletin No. 45 of the Agricultural Research Institute, Pusa, and has been investigated by Mr. D. L. Sahasrabuddhe. The secretion which is used as a medicine in Western India has been found to consist of a mixture of malic and oxalic acids in the proportion of 94 per cent. of the former and 6 per cent. of the latter, and the secretion appears to be produced by the glandular hairs which occur especially upon the pods. The acids are collected by drawing a damped cloth over the gram vessel, and during the ninth to the eighteenth week plants and then wringing it into an earthenware of the plant's growth the yield of malic acid for an acre of gram was found to be 2686 gm., the cost of collection being about 14 rupees.

THE twisted fibres of the chir pine (Pinus longifolia, Roxb.) again forms the subject of an article in the Indian Forester. In the number for April (No. 4, vol. xli.) Mr. F. Canning deals with the matter as regards the east of Almora district. Twisting both left-handed and right-handed is found, and a very large proportion of trees are affected. At the base the twist is usually slight, and it becomes worse and worse higher up the stem, the maximum angle noted being 45° from the vertical. As to the distribution of affected trees, the relation to the geological conditions has not been observed, but aspect, fire, and proximity to villages do not appear to be correlated in any way with the occurrence of twist. Owing to the difficulty of detecting twisted trees in the young state, it may not be practicable to try to eliminate twisted fibre specimens in a sapling forest, though such trees are of very little value except for firewood.

THE Salton Sea in the Cahuilla Basin of California is described and illustrated by Mr. D. T. MacDougal in the American Journal of Science (vol. xxxix., p. 231). The work published by the Carnegie Institution was reviewed in NATURE (vol. xciv., p. 434, December 17, 1914), and this shorter account will be convenient for many who have not access to the publications of the institution.

MR. H. P. CUSHING (American Journal of Science, vol. xxxix., p. 288) criticises the view of Prof. W. J. Miller that the syenites and granites of the Adirondack region belong to one vast intrusive body, and maintains that here, as in Canada, there is an older group of orthogneisses which is intruded into the Grenville Series. This group has suffered severe regional metamorphism, and has been invaded by later rocks of the anorthosite-syenite group. The older orthogneisses may therefore be styled Laurentian, as in Canada.

THE expedition of Mr. F. B. Loomis from Amherst College to Patagonia resulted in his discovery, published in 1914, that Pyrotherium was a proboscidean. He referred the beds in which it occurred to the Oligocene. Mr. Carlos Ameghino ("Boletin de la Sociedad Physis," vol. i., p. 446, Buenos Aires, 1914) states that certain white sandy clays underlying the Pyrotherium beds, and recognised by Loomis as Cretaceous, are the strata that contain Notostylops, Notopithecus, and other mammals. Ameghino accepts a Cretaceous age for these, and believes that Pyrotherium is an early Eocene form. If this were proved, the ancestry of the proboscideans is to be sought, as Ameghino urges, in S. America rather than in Africa.


THE paper entitled "The Microspectroscope in Mineralogy," by Mr. Edgar T. Wherry, assistant curator of the division of mineralogy and petrology in the U.S. National Museum, which forms No. 5 of vol. lxv. of the Smithsonian Miscellaneous Collection, constitutes an important contribution to our knowledge of the absorptive properties of minerals. long ago as 1866 Sir Arthur Church first noticed the existence of an absorption spectrum in zircon, but hitherto no systematic study has been made of the subject. Mr. Wherry has examined specimens of about two hundred minerals, and the results of his investigation are carefully tabulated. The analytical key given at the end of the paper should be invaluable to those making use of the method for determinative purposes. He found that better results were afforded by light diffused from the specimen than by light transmitted through it. The beautiful violet calcite from Joplin gives the neodymium absorption spectrum, and so do the yellow sphene from Switzerland and the brown apatite from Ontario. It is unexpected to learn that the colour of the violet-red almandine garnet is apparently due to vanadium. presence of magnesium and manganese has no effect upon the colour of garnet. The bands shown by zircon are due to the presence of uranous uranium, usually in amounts of less than o'5 per cent. The resulting blue colour is often masked by the other agents, such as iron or manganese. Brown or white zircons do not show a spectrum.


[blocks in formation]


centages of the total fall are given for each interval of four hours. The highest percentage value is 22-0 for 4 to 8 p.m., and the lowest 12.2 for 8 a.m. to The results for Petrograd are for the twelve years 1897 to 1908, and have been dealt with in the same way. The highest percentage is 22.3 for noon Both to 4 p.m., and the lowest 13.3 for 4 to 8 a.m. stations are fair representatives of the Continental type, and show a maximum in the afternoon and a minimum in the morning. Karlsruhe is said to have a diurnal range of rainfall highly resembling that of Perpignan, for which the percentages are given. Petrograd shows great similarity to Kew, the results for which are given from "The Diurnal Range of Rain," issued by the Meteorological Council.

THE Journal of Agricultural Research, iii., 5 (Washington), is scarcely the place in which one would expect to find a paper on fitting logarithmic curves by the method of moments. The use of logarithmic curves would appear to be desirable for tabulating biological statistics, and the object of the paper is to determine the constants when the formula assumed is of the form of a quadratic function plus a logarithm. Mr. John Rice Miner determines these constants in terms of the area and first two or three moments of the curve, but unfortunately the formulæ are very laborious in the carrying out, and it would certainly appear desirable to simplify them.

THE Journal of the Washington Academy of Sciences for May 19 contains a short account of a new calorimeter due to Messrs. H. C. Dickinson and N. S. Osborne, of the Bureau of Standards. The calorimetric substance is a block of copper in which are embedded a platinum resistance thermometer and a coil of resistance wire for supplying heat to the block electrically. A number of test experiments on the specific heat of water show that a degree of accuracy of 1 part in 2000 may be obtained with the calorimeter. The specific heat between -40° C. and o° C. and the latent of fusion of ice at o° C. have also been determined with the apparatus. The results for the specific heat are given by the expression 0-5057+0-001868, where is the temperature Centigrade, and for the latent heat 79.76 in terms of the gram-calorie at 20° C. The latter figure is in close agreement with the value 79.74 previously obtained at the Bureau by other methods, so that it seems probable that the mean 79.75 may be accepted as a close approximation to the true value of this important constant.

M. ERNEST COUSTET contributes to La Nature of May 22 a useful article on the dosage of X-rays. He admits that the mere observation of the current traversing the X-ray tube is apt to be very misleading. Better results are given by comparing the fluorescence produced by the rays with the fluorescence produced by a radium bromide standard. This method implies a careful observation of the time of exposure, a necessity which is avoided by the various "chromometers" devised by Holzknecht, Bordier, Sabouraud, and Noiré, in which the dose is estimated by the coloration of sodium chloride or bromide, or of barium platinocyanide. Since, however, the estimation of tints does

[ocr errors]

not admit of any great accuracy, some ionisation method appears preferable, such as is employed in Villard's X-ray counter, in which an electroscope is discharged a number of times. It then remains to measure the hardness" of the rays, or their penetrating power, and this may be done by Benoist's "radiochromometer," consisting of a ring of aluminium strips of twelve different thicknesses. There is still, however, much room for improved methods of dosage.

MR. JAMES KEITH directs attention in the Engineer for June 11 to the use of cast-iron shells of fairly large calibre by the Germans. Mr. Keith suggests that, whether or not there be any particular reason for our keeping to expensive steel shells, there could surely be no harm in our having cast-iron ones as well to fill up the gaps, and so enable innumerable shells to be at the service of the armies of the Allies. The matter is taken up by our contemporary in a leading article, and the objections to the course suggested by Mr. Keith are discussed fully. In shrapnel cast-iron shells, the number of bullets is reduced because the walls of the shell must be made much thicker. In high-explosive shells there is such `danger of a cast-iron shell developing cracks during manufacture that high explosives cannot safely be used in them. Further, projectiles must be perfectly in balance; the walls must be of uniform thickness all round, and must be of homogeneous material. Otherwise accuracy in shooting would be destroyed. Lastly, the methods of manufacture of steel shell have been so developed that such shell can actually be turned out more quickly than those of cast-iron of equal trustworthiness and accuracy. An 18-pounder shell can be completely machined from the bar in about forty minutes. The Engineer suggests that the use of castiron by the Germans indicates that they are finding their supplies of modern projectiles not inexhaustible under the tremendous drain that is being put upon them.

MESSRS. LONGmans and Co. announce for early publication "The House Fly: a Slayer of Men," by F. W. Fitzsimons, director of the Port Elizabeth Museum. The volume will be illustrated. The author has worked for several years at the destruction of the house-fly in South Africa.


OUR ASTRONOMICAL COLUMN. BEHAVIOUR OF SPECTRUM LINES OF THE SAME SERIES. -The lines in a series are generally assumed behave alike (omitting reversals), even under varying experimental conditions. In fact, their sharpness, diffuseness, or direction of unsymmetrical widening have been used as criteria in the detection of series relationships. Thus if the strong lines of a series were unsymmetrically widened towards the red the remaining lines of the series would be expected to be widened in the same direction. This, however, is not the case, and an investigation bearing on these points is communicated by Dr. Royds to the forty-third Bulletin of the Kodaikanal Observatory (see also the Astrophysical Journal, March, vol. xli., No. 2, p. 155). In the case of the barium lines he finds that all the first members of the first subordinate series are dis

placed to the red, and the second members to the violet. In the case of the calcium series he finds this not so extreme a case as that of barium, but still a noteworthy exception to the general run of series. The strontium series, on the other hand, is stated to be quite normal if the infra-red lines the character of which is unknown are excepted. Dr. Royds directs attention to the whole question of the relationship between pressure shifts and series, since the pressure shift may even be in opposite directions for lines of the same series. He points out, further, the importance of isolating the pressure effect from the density effect, the elimination of the latter in order to obtain true pressure shifts being one of the most pressing problems for those interested in the displacements in the sun's spectrum."

THE FISHER, POLK COUNTY, MINNESOTA, Meteorite. -In the American Geologist for December, 1894, brief mention was made of the finding near Fisher, Polk County, Minnesota, of a meteoric stone weighing nine and a half pounds. This stone, the first found within the State limits, was assumed to be a representative of a reported fall which took place on the 9th of the preceding April. In a subsequent number of the Geologist a petrographic description of the stone was begun by Prof. N. H. Winchell, but this was neither completed nor was a satisfactory chemical analysis made. In view of these facts and also because more parts have been subsequently found, a complete review of the whole matter has been undertaken by Prof. G. P. Merrill, and the results are published in No. 2084 Proceedings of the United States National Museum (vol. xlviii., pp. 503-6, May, 1915). It seems that specimens of this fall are distributed in eight different collections, the four largest portions being in institutions in Minneapolis, Washington, New York, and Hamburg; the total weight of all the known portions amounts to 9900 grams. The author has been offered facilities for examining and taking samples for the purposes of identification and chemical analysis, and in this paper he publishes the results of his inquiry. Following Brezina's classification he places the stone in the group of intermediate chrondites Ci, or perhaps Cia, as one cut surface shows a small thread-like black vein.

THE NANTUCKET MARIA MITCHELL ASSOCIATION.-In the thirteenth annual report of the Nantucket Maria Mitchell Association, an account is given of the astronomical work accomplished during the past year. This association completed in 1911 the Astronomical Fellowship Endowment Fund, and the first fellow was appointed in the following year; the second has just been nominated. This fellowship enables the holder to avail herself of the entire year for study and research in an observatory of her own selection. Miss Annie J. Cannon, the chairman of this special committee, describes briefly the work of the association with the new 7 in. photographic telescope. After the adjustments were completed numerous photographs were taken, chief of which were of the minor planet Eros. These plates are now being measured by the first fellow, Miss Harwood, at the Harvard Observatory, together with the plates of the same asteroid taken at that observatory. The chief research will be the photographing of each asteroid once a month for as long a period as possible, the selected objects being those for which the ephemeris at opposition is given in the Berlin Jahrbuch.

RECENT BULLETINS OF THE ASTRONOMICAL SOCIETY OF FRANCE. The April and May numbers of the valuable Bulletin of the Astronomical Society of France have come to hand in spite of the difficulties under which

such a publication is produced. The publishers, in a special note, direct attention to these difficulties, and say that the Astronomical Society of France, confident in the triumph of right and of civilisation, pursues, by the publication of this monthly Bulletin, its work of instruction and scientific propagation with untiring energy, and counts on its adherents to forward at once their subscriptions for the current year. The two issues mentioned above contain numerous communications of interest, among which may be mentioned the first observations of the transit of Mercury, an episode in the life of François Arago, an address by Monsieur C. Flammarion, delivered at the annual general meeting of the Society on April 11 of the present year, and a summary by Comte de la Baume Pluvinel, at the same meeting, of recent discoveries in astronomy. The application of selected filters to the study of Comet Delavan is described by Mentore Maggini, being a summary of a research he undertook in the year 1913.


DR. J. E. STEAD'S knowledge of iron-carbon

phosphorus compounds is so remarkable, and indeed so unique, that the recent meeting of the Iron and Steel Institute in London was rendered memorable by his presentation of a most illuminating paper on this subject. As a matter of fact, the word "paper" is an inadequate description of the publication, which is very composite in character and deals with some ten aspects of the iron-carbon-phosphorus equilibrium; most of them practical, some of them purely scientific.

The constitutional diagram of the iron-carbonphosphorus alloys is not yet completely known. The studies of Stead, Wüst, and Goerens have established with sufficient accuracy the liquidus fields of that part of the triangular diagram the corners of which are represented by iron, iron phosphide, Te,P, and iron carbide, Te,C. The compositions of the three "binary eutectics are known, as is also that of the ternary eutectic, which contains 91'19 per cent. of iron, 192 per cent. of carbon, and 689 per cent. of phosphorus, and freezes at about 950° C. But, in spite of the fact that the paper under notice contains much new and interesting information about some of the solid phases and their relations between the solidus and the ordinary temperature, we are still without accurate knowledge of the composition of most of them and their variation with varying temperature. The constitutional diagram below the solidus has still, for the most part, to be determined, and until this has been done the interpretation of a good many of Dr. Stead's results can only be provisional.

In some earlier experiments Dr. Stead squeezed a portion of the ternary eutectic out of grey Cleveland iron by pressure. The amount extruded, however, was only a small fraction of the total quantity present, for the mould was not maintained, as it would have had to have been, at a temperature just above the freezing-point of the eutectic. It appears, however, that the requisite temperature and pressure conditions are realised in the formation and very slow cooling of the so-called "blast furnace bears." These are accumulations of grey iron which gradually form underground below the well or crucible of the furnace, and sometimes attain an enormous size. One of these dug out from beneath one of the Skinningrove furnaces weighed between 500 and 600 tons. The circumferential contraction of this large mass on cooling compressed the central portion, which was the last to freeze. According to Dr. Stead, "the effect of this

enormous pressure caused the central plastic mass to assume a vertical column, an arrangement closely resembling on a small scale the basalt of Giants' Causeway." These columns could be separated from one another. Chemical analyses indicate that about 90 per cent. of the phosphorus originally present had been extruded vertically between the columns during the period of intense compression. A "bear" with a similar columnar structure has also been found in the hearth of a Cleveland furnace of Messrs. Bolckow, Vaughan and Co. at Eston. Here, too, the columns were all vertical, and varied from to in. in diameter, and in some places were so loosely attached to each other that they could be separated by hand. These also were found to be low in phosphorus. In the case of a bear under an Ormesby furnace which had been in blast some thirty-eight years, about twothirds of the original phosphorus had been removed, but there were no indications of columnar structure. On the other hand, the metal found in the hearth of one of the furnaces at Ferryhill consisted of columnar crystals of iron saturated with iron phosphide, with walls of iron phosphide, but entirely free from carbon and silicon. Here, therefore, the conditions must have been much more oxidising, and no ternary eutectic was present. It is, however, abundantly clear that by far the greater part of the phosphorus in highly carbonised iron is concentrated in the last portions which freeze.

Two photographs reproduced in Dr. Stead's paper illustrate the structure and mode of occurrence of the ternary eutectic extremely well. Both were developed by heat-tinting, iron phosphide appearing blue or purple, iron carbide red, and iron saturated with phosphide white. No. I is termed by Dr. Stead the "normal" structure, and is clearly lamellar, recalling the well-known pearlite in its form; No. 2 is evidently that of a very slowly cooled specimen, the lamellæ having coalesced to an appreciable


[ocr errors]

The equilibrium relations between iron, iron carbide, and iron phosphide in the range of temperature 1000° C. to 700° C. are of the utmost importance in the light they shed on the so-called 'ghosts" or "phantoms," which are very liable to occur in large forgings of mild or medium steel. These are lines or streaks which can only be detected after rough turning. As the names indicate, they are not deep-seated. They are completely removed by turning off a thin layer of the steel, but are liable to reappear in other places. It is clear, therefore, that they are very attenuated and irregularly distributed. The usual view held is that they are harmful, and forgings are sometimes rejected on account of their presence, in spite of the undoubted fact that some of them have proved satisfactory in service even though such ghost lines were present. Their occurrence, in Dr. Stead's view, is due to the fact that "in steels containing o'45 per cent. and less carbon, although the carbon may be equally distributed when the steel is at 1000° C., on very slow cooling the ferrite first appears in the parts richest in phosphorus. The portions which are partially saturated with phosphorus cannot so readily hold in solid solution at certain temperatures as much carbon as the surrounding portions which contain little or no phosphorus; consequently, when in cooling it reaches these temperatures, the carbon diffuses out of the phosphorised parts into the surrounding pure metal." These areas of phosphide concentration constitute the ghosts, and, as sulphides and phosphides segregate together, sulphides are generally present in them as well.

Dr. Stead has succeeded in producing typical ghost lines synthetically by heating to 1000° C. strips of soft

iron sandwiched with ternary eutectic and then forging down to a-in. sheet. This treatment squeezed out the excess of eutectic and left the juxtaposed faces perfectly united with a thin layer rich in phosphorus. After very slow cooling, sections were cut, polished, and etched. The structure was found to consist of "strings of disconnected patches of pearlite and straight lines of ferrite," very similar to those found in ship and boiler plates. All the carbon originally present in the eutectic was found to have diffused into the iron beyond the phosphoretic junctions Heating to 1350° C., however, followed by a three days' cooling period to 700° C., caused a uniform distribution of the carbon and phosphorus in the steel.

Dr. Stead's general conclusion is: After careful study I am inclined to believe that if they "-i.e. ghost lines are not associated with a material amount of slag inclusions, they are not dangerous or liable to lead to the failure of engineering structures. I am led to that conclusion by submitting cross-sections to violent shock test, so that the stress applied is greater across the lines; for when this is done fracture does not start where they are located unless there are sulphide or slag inclusions in material quantity. The subject should have more consideration, and be thoroughly investigated by making suitable mechanical tests."

Only two aspects of Dr. Stead's publication have been touched upon in this article. The complete paper, however, should be studied by those who are interested in the presentation of the subject in a series of masterly and informing sub-papers which no one but he could have written.





OUR volumes of the Bulletin of this society were completed with the last year. They contain many papers of interest and value, most of which have been noticed in these columns, and several -evidently the work of novices-which the Publication Committee might with advantage have suppressed.

The first part of the fifth volume, which has been issued recently, contains six papers, three of which are of general interest. Of the others, one on the seasonal periodicity of earthquakes is inconclusive. Mr. Carl H. Beal describes an earthquake which originated near the town of Los Alamos, in southwestern California, on January 11 last. This is probably the first earthquake in which the long-distance telephone has been used in the collection of records. Prof. J. C. Branner insists on the untrustworthiness of personal impressions on the direction of an earthquake-shock, and he urges that, in investigations of an earthquake, the question dealing with such impressions should be omitted. It has long been known that single observations on the apparent direction of the shock or on the fall of a column, etc., are valueless, the apparent direction being almost invariably perpendicular to the principal walls of the house in which it is observed. But the average of a large number of personal observations within a limited area has been found in several cases to coincide with the direction of the area from the epicentre. Moreover, after the Tokyo earthquake of June 20, 1894, Prof. Omori measured the direction of fall of 140 stone lanterns with circular bases in Tokyo, and the average of these measurements coincides exactly with the direction of the single great oscillation registered in that city.

The first place in the number is given to Mr. Carl H. Beal's account of the Avezzano earthquake of January 13. The material of this paper is derived chiefly from newspaper reports and from a short article which appeared in NATURE (vol. xciv., p. 565), but the author adds an interesting note with regard to the origin of the earthquake. The higher mountain ranges near Avezzano," he says, "rise to an altitude of from 6000 to 7000 ft. and trend generally north-west and south-east, the direction apparently being determined by a series of nearly parallel frac tures which extends from a region south-east of Avez zano north-west to the vicinity of Cittaducale. A fault is known to pass through Luco, Cappelle, Sourcola, and very close to Avezzano, and as these cities were completely demolished, it is quite probable that movement along this fracture caused the shock." On November 8, 1914, a fairly strong earthquake was felt in central California. From the duration of the preliminary tremors at Berkeley, and from the initial times at Santa Clara and the Lick Observatory, and taking the velocity for the tremors at Zeissig's value of 6.3 km. per sec., Mr. E. F. Davis finds that the epicentre was situated on the San Andreas Rift, close to the town of Laurel. From a study of the distribution of intensity, Mr. Carl H. Beal had previously assigned approximately the same position for the epicentre. The San Andreas Rift is the great fault along which for 270 miles the movements took place which gave rise to the Californian earthquake of 1906.

Since 1832, there have, according to Mr. H. O. Wood, been twenty-five eruptions of Mauna Loa, in the south of Hawaii. With the majority of these no earthquakes are recorded, and this might also have been said of the last eruption which began on November 25, 1914, had it not been for the instrumental record of a large number of feeble shocks. Mr. Wood concludes that "nothing appears in the sequence of events which would have justified confident, or definite, prediction of outbreak," though the numbers of shocks recorded during the five preceding weeks were one, five, sixteen, thirteen, and thirty-eight.



THE two volumes referred to below supplement one another, for while the general report gives an abbreviated account of the year's work, more detailed descriptions and the discussions of the results obtained find their place in the Records.

Pendulum observations were made at fourteen stations between lat. 20° N. and lat. 30° N., all in the immediate neighbourhood of the 78th meridian, thus filling in the gap which existed between Lieut.-Colonel Lenox-Conyngham's work from Mussoorie to Meerut, and that of Captain Cowie in the Central Provinces. The stations include that of Kalianpur, the station of origin of the Indian triangulation, and here the pendulums were swung in the same room where Captain Basevi swung his pendulums in 1867. At Dehra Dun the new pendulum room was used. Some changes have been introduced in presentation of the results; Helmert's formula of 1901 is employed instead of that of 1884, which had been used previously; also the formula for the mass correction has been modified by taking somewhat smaller values for the mean surface density of the

1 "General Report on the Operations of the Survey of India during the Year 1912-13." By Colonel S. G. Burrard, C.S.I., R.E., F.R.S. (Calcutta, 1914.) Records of the Survey of India." Vol. v., Reports of Survey Parties, 1912-13. (Calcutta, 1914.)

« PrejšnjaNaprej »