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plicable to many cases where more troublesome apparatus would be out of place. His arrangement consists essentially in such an alteration of the well-known printing barometer constructed by G. W. Hough, of Albany, that the use of electricity is done away with, and, on the other hand, the fulcrum of the principal lever in the apparatus is fixed, while the barometer tube itself, or the aneroid box, moves. The numerous specimens of the apparatus constructed by Redier for individuals in France seem to have given very general satisfaction, and the instrument has been highly commended to the attention of French observers. It consists essentially of a clockwork by means of which a cylinder is made to revolve uniformly, carrying with it a sheet of paper upon which the record is to be made. Above the cylinder stands the barometer, which is so arranged that the rise and fall of a thousandth part of an inch causes a lever to rise or fall by a corresponding movement, thereby releasing the detent of an auxiliary piece of clockwork, which is thereby at once set in motion. The movement of this clockwork allows the barometer tube itself to fall or rise, thereby again interfering with the movement of the clockwork and automatically stopping it. Meanwhile the up or down movement of the barometer has been closely followed by the corresponding movements of a pencil, whose mark on the sheet of paper produces an exact record of the extent of the barometric change.-13 B, III., 267.

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DO STORIS CROSS THE ATLANTIC ? Mr. Ley states that, having worked for a considerable time at the comparisons of United States with European weather charts, he concludes that only a small portion of the storms experienced on the American side of the Atlantic can subsequently be distinctly traced in Europe. Of those thus traceable the majority are felt severely in the extreme north of Europe. The rapidity of the progress of these storms across the Atlantic varies indefinitely, and could not be deduced, as Mr. Draper has attempted, from the velocity of the winds experienced in them. Many of the most destructive European storms occur when the barometric pressure over the castern portion of the United States is tolerably high and steady, and they appear to be developed upon the Atlantic

Ocean, near the eastern limits of the area of high pressure. 12 A, 405.

GLACIATION OF ICELAND. In the opinion of Mr. William L. Watts, who is engaged in making some explorations among the glaciers of Iceland, these are increasing year by year; and he thinks that at no distant period the whole island will be covered with ice, as is the case with Greenland.-13 A, 193.

GLACIERS OF THE HIMALAYAS. At the recent meeting of the British Association Colonel Montgomerie gave an account of the glaciers of the Himalayas, which are most developed in Baltistan, in Northwestern India. According to his statement, these glaciers gradually increase in size from east to west, many of them being more than twenty miles in length, and one, Biafo, thirty-four miles. The thickness of the ice was in some cases found to be 400 feet. The phenomena of progress, etc., were found to be similar to those observed in the Alps.--15 A, September 4, 314.

TIDES OF TIIE MEDITERRANEAN. The tides of the Mediterranean form the subject of a prize essay by Stahlberger, of Hungary. The author especially dwells upon observations and discussions relating to the peculiar local influences in the neighborhood of the port of Fiume, on the shores of the Adriatic. Pursuing an inductive method, he shows the existence of general changes of the water produced by cosmical causes, and local changes due to meteorological or local agencies. Of the former there are principally two oscillations dependent on the sun, and two on the moon. The local changes are caused chiefly by variations in the wind and the barometer. In stating this view, he seems not to have gone beyond what Mr. Ferrel has already published with reference to the Atlantic.—"Mitth.Austrian Hydrogr. Office, II., 723.

DAILY WEATHER CHARTS. The dissemination of valuable meteorological intelligence has been remarkably facilitated in England by the daily publication, in the London Times, of a small weather chart, show

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ing the temperature, wind, barometer, and weather, and the condition of the sea for the region within about five hundred miles of London. This chart is prepared daily by the London Meteorological Office, and furnished gratuitously to the newspapers. The stereotype plate, fit for use in a Walter printing-machine, is produced in about an hour. It is now more than four years since a similar undertaking, on a some. what different scale, was set on foot by Sir William Mitchell in the Shipping Gazette of London, and which has been continued daily.

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CONNECTION OF WEATHER AND COLLIERY EXPLOSIONS. Messrs. Scott and Galloway, of England, have continued their researches into the connection between colliery explosions and the weather. As the result of the study of two hundred and twenty-four explosions, they state that the amount of fire-damp recorded in the mines increases and diminishes directly as the barometer falls and rises, proving beyond the possibility of cavil that the variations of atmospheric pressure have a marked influence on the rate at which fire-damp escapes from fissures. In the large majority of the fatal explosions the miners were using naked lights; and they suggest that if fire-damp is known to be present in any part of the mines, then either the workmen should not be allowed at any time to be near it, or else they should use safety-lamps in its vicinity, at least during the continuance of the barometric depressions. They also suggest the interest and value that would attach, both in a scientific and a practical point of view, to the keeping at coal-mines of barometric records, such as are daily furnished by the self-recording apparatus which can now be obtained from every meteorological office.—Quart. Jour. Met. Soc., London, II., 195.

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THE HOURLY DISTRIBUTION OF RAINFALL, Among the very few meteorological stations at which the rainfall has been recorded either continuously or hourly is to be noted that of Berne, in Switzerland, the observations at which place for the past eight years have recently been studied by Forster. The diurnal periodicity of rainfall, both as regards its quantity and its frequency, follows at this place a regular law, and, on the average of the year, it is shown

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that the probability of rain increases from one o'clock in the morning to a maximum at seven o'clock in the morning, then sinks to a minimum at two o'clock in the afternoon, and rises again to a maximum at midnight. The diurnal period is thus almost opposite to that which obtains under the tropics, where in the afternoon, at the hour at which the temperature is at its maximum, and at which the clouds are, on the average, the highest above the earth, it rains most frequent ly.-19 C, VII., 234.

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PERIODICITY OF SEVERE WINTERS. A memoir by Rénou, the distinguished French meteorolo. gist, upon the periodicity of severe winters, although published many years ago, has been recently quoted in defense of the opinion that such periodicity actually exists. According to Rénou, rigorous winters return about every forty-one years. They are arranged in groups, generally composed of a central winter, and four or five others disposed on either side of it, within a space of twenty years. Mixed with these years are others, also, of unusual warmth, in such a manner that the mean cold of the season is not sensibly altered. The period of forty-one years seems to be that which corresponds to the maxima of the solar spots at the same season of the year. A central cold winter arrives eighteen months after the maximum of spots has coincided with the warmest season of the year. The severe winters seem to alternate between the northern and southern hemispheres of the earth. -13 B, 135.

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ORIGIN OF THE CENTIGRADE THERMOMETER SCALE. According to the historical notes contained in the meteorological observations of Lafou, president of the Meteorological Commission of Lyons, the first thermometer that was ever seen at Lyons was brought thither in February, 1736, by Duhamel, to Father Duclos, director of the observatory founded by the Jesuits in the chapel of their college. This thermometer was constructed with alcohol, according to the principles of Réaumur, and was used for some time. A member of the Academy of Lyons, named Christin, replaced the alcohol by mercury, as had, indeed, previously been done by Fahrenheit in 1724, and by Dr. Sauvage at Montpelier in

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1736. Christin baving introduced into a tube terminated by a bulb a quantity of mercury, whose volume might be represented by 6600 at the temperature of freezing water, found that this volume became 6700 when the tube was plunged into boiling water. The alcohol of the original thermometer being thus dilated 100 parts, Christin divided the corresponding space passed over by the mercury into 100 equal parts, remarking that these new divisions, being smaller than those of Réaumur, would be more in barmony with the sensations caused by variations of temperature. Such was the origin of the Centigrade thermometer, which was afterward known for a while under the name of the “Thermometer of Lyons.” Four years after--that is to say, in 1746—Cassini, who was a well-known optician at Lyons, had sold seven hundred of these in Paris, besides others in Provence and Dauphiny.-13 B, III., 94.

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PERIODICITY OF HAIL-STORMS, The tendency which has been so marked of late years to look for a periodicity in almost every natural phenomenon corresponding to the periodical increase and decrease of the solar spots, seems to have been carried to its fullest extent in the recent suggestion of Professor Fritz, according to whom the frequency of hail-storms has some connection, accidental or otherwise, with the frequency of solar spots. He finds, by collecting the records from twenty-five different European and other stations, that all observations show that the years of greatest frequency since 1806 have been 1817, 1830, 1838, 1848, and 1860, which years follow or are nearly coincident with the sun-spot maxima of 1817, 1829, 1837, 1849, and 1860; whence it would follow that the year 1871, a year of sun-spot maximum, should be also a year of frequent hail-falls, as actually was generally recorded. Furthermore, seasons of infrequent hail-storms correspond to the minimum of solar spots, as in 1810, 1823, 1834, 1844, and 1856. It has also been often remarked that a winter of extensive or frequent auroras is followed in the succeeding summer by unusual hail-storms. The connection between auroras, lightning, hail, and cirrus clouds and the solar spots seems, therefore, worthy of further study.—7 C, XV., 244.

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