CURRENT NOTES ON METEOROLOGY.

BAROMETER AND WEATHER.

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UNDER the title Barometer und Wetter,' van Bebber discusses, in the Archiv der Deutschen Seewarte (Vol. XXVII., 1904, No. 2, pp. 1-15), the use of the barometer as a 'weather glass,' for foretelling changes of weather; refers to the studies already made to determine the barometer readings which correspond to certain weather conditions, and then investigates the relation between the readings at Hamburg and the rainfall, temperature and cloudiness, for the year, seasons and individual months during the period 1876-1900. It appears that rain falls very infrequently when the barometer is very high; that it is then extremely light, and comes only in the colder months. Rain probability shows a steady increase with decreasing pressure; at extremely high pressures (over 30.50 ins.) there is no precipitation, and at pressures below about 28.90 ins. there is always precipitation. As to temperatures, the departures are negative at the higher pressures and positive at the lower, when averaged for the year. At low pressures the departures are positive in winter and negative in summer. Cloudiness is at a minimum during highest barometric pressure, and at a maximum during low pressure. In winter, however, high pressures are usually accompanied by fog. In Central Europe most of the precipitation of the colder months comes with falling, and of the warmer months with rising pressure, while in the British Isles and over the North Sea area it comes with falling pressure in all seasons. The critical study of these relations of pressure and weather, conditions, which are set forth numerically in his paper, leads van Bebber to the conclusion that a reasonably accurate judgment of existing and coming weather can be based on the readings of the barometer, especially when the location of the cyclonic and anti-cyclonic centers can be learned from the newspaper reports. The last paragraph in the article is a quotation from a publication by the same author, dated 1899, to this effect: An experience of twenty-five years has brought Dr. van Bebber to the conclusion that no reorganization of weather ser

vice work would be of any value if the present forecasts for a single day following are adhered to. These forecasts have not satisfied the agricultural interests and will not satisfy them in the future. Nor will the forecasts be satisfactory unless the general public understands better than at present the basis on which weather predictions rest.

Dr. van Bebber's work along the line of public education in weather types, and what these types means has been a most valuable one, and the present investigation, which might well be carried on for any number of American stations, is a useful extension of his previous studies.

MONTHLY WEATHER REVIEW: ANNUAL SUMMARY, 1904.

THE value of back numbers of the Monthly Weather Review has in the past been very much decreased by the fact that an adequate index has not been prepared for each volume. The index hitherto published has been an author index, arranged alphabetically so far as the authors' names were concerned, but not arranged alphabetically so far as the titles of the papers were concerned. The result has been a large and wholly unnecessary expenditure of time in looking up some special article or note. For the year 1904, we are glad to see, there is a fairly adequate author and subject index, arranged alphabetically as a whole, although the separate articles under different subject-headings are not in all cases alphabetically arranged. Thus, for example, to take only one case, under 'Observatories' we find the following:

pared the index for 1904, and will hope that he may have time next year to make a more complete index for the 1905 volume.

CLIMATE OF JERUSALEM.

PROFESSOR G. ARVANITAKIS, in the Bulletin de l'Institut Égyptien (4th ser., No. 49), has published a series of meteorological observations taken at Jerusalem, as well as some notes on the climate of that region. The winds from the east are extremely dry, coming as they do from the Arabian deserts. Rain comes from the western quadrants. Hail is noted as being fairly common in Palestine, and a source of injury to the fruits. The observer says that he seldom saw a heavy rainfall unaccompanied by hail. Cisterns and reservoirs supply water during the dry season of summer, and the heavy dews are very beneficial to vegetation. These dews are characteristic of Palestine, and must be seen to be fully appreciated. The climate is not described as very healthful. Dysentery, fever and rheumatism are not uncommon at Jerusalem, especially during the summer months.

MARINE METEOROLOGICAL SERVICE OF CHILE.

THE meteorological work carried on at the coast stations of Chile, from Arica in the north to the Strait of Magellan in the south, is under the direction of the so-called 'Direccion del Territorio Maritimo' of Chile. Up to the year 1899 this work was in charge of the central observatory at Santiago. An annual volume (Anuario) is issued, giving complete tabulations of the data for each of the eighteen stations, and including monthly and annual summaries. Thus far (1903, Vol. V., issued 1904) no discussion of these observations has been included. These littoral stations of Chile have the great advantage of varying but little in their longitude, and of being very near sea level, so that there is much uniformity in these respects. The great climatic interest of Chile, which results from its peculiar position with reference to the Cordillera of South America, and from its extraordinary contrasts in rainfall between the arid north and the rainy south, lends exceptional

value to any such data as those included in the volumes here considered.

R. DEC. WARD.

NOTES ON FORESTRY.

WHY PRAIRIES ARE TREELESS.

IN a paper by Alfred Gaskill read before The Society of American Foresters, February 23, the theory that forest fires are responsible for the treeless condition of the prairies was advocated. In support of this by no means new theory, Mr. Gaskill cited some geological, physiographical, climatological and silvical facts which, in his opinion, `point most emphatically to the fire origin of all true prairies. He divides the treeless area in the United States into plains and prairie. The former are treeless, primarily because of deficient moisture, and were so from time immemorial. It is different, however, with the prairies; they offer conditions favorable to tree growth and, therefore, their treeless condition presents a riddle clamoring for solution. The great prairie of the United States occupies an irregular area bounded on the east by a line that follows in a general way the ninety-fifth meridian and on the west by a line roughly extending along the ninety-seventh meridian. The eastern boundary is most irregular, its shape corroborating the fire origin of the prairie. In the north it makes a great bend eastward, enclosing half of Iowa, more than half of Illinois, and portions of Wisconsin and Indiana. Along its whole extension the prairie forms lobes and long tongues thrusting eastward into the forest. Since it is proved by the records of the Weather Bureau that the western boundary is within the limit of sufficient rainfall, capable of supporting tree growth, the whole area now occupied by the prairie is situated where forest ought to be, for there is neither lack of rain nor any condition in the soil or the vegetation that will account for the absence of trees. Mr. Gaskill assumes, therefore, that something not entirely normal caused the forest to retreat from its proper position. After a careful and detailed study of the records of forest and prairie fires in the states of Montana, Wyoming, Colorado, Texas, South

Dakota, Nebraska, Kansas, etc., he found that most of the fires occur there in the fall when the prevailing winds are from the west, and the vegetation of the plains lying to the windward of the area now prairie is exceedingly dry and combustible. The habit of the Indians of setting fire to the grass of the plains at that time of the year and its annual occurrence are matters of history. These annual fires, driven by strong westerly winds and finding no obstacle to their progress in the flat or gently rolling land, spread eastward until they reached the green timber. Year after year these fires ate their way a little farther into the forest, making the dense forest first more open and eventually entirely consuming it. The irregular projections of the prairie eastward into the forest are considered by Mr. Gaskill as the result of the work of the fires. Another evidence of its influence in causing the prairie he finds in the fact that with the settlement of the country and gradual elimination of fires the forest commenced to gain again on the prairie.

The prairies in other countries were also considered from the same point of view, and the speaker suggested that local students would probably confirm his opinion that fire has been an active agent in all such regions.

PRINCIPLES INVOLVED IN DETERMINING FOREST

TYPES.

ON February 23 Mr. Raphael Zon read before The Society of American Foresters a paper on forest types. These he identified as tree associations in the ecological sense, and not mere aggregations of trees as they often are conceived to be. Few will dispute the statement that the forest type is the cornerstone of silvics, and that the proper recognition of types in any forest is the first and most important question that a practical forester has to answer. “* * * The division of a forest into natural types of growth, however, is not such a simple thing as it may appear at the first glance. Stands differ from each other in many respects; they may be pure or mixed, even-aged or irregular, dense or open, of seedling or sprout origin, etc. Which of these features justifies the subdivision of the forest

*

into types of growth, and what must we call a natural forest type? * * When we attempt to trace to some definite causes the differences between stands composing a large forest, we finally come to two main ones: first, external physical conditions, such as climate, soil, moisture in the ground, topography, exposure, etc.; and second, interference by man, and natural accidents, such as fire, wind and * * * It does not take very long to realize that segregating stands into types based on density, age or mode of origin can not be justified, since such features are not permanent and can not be characteristic of any definite forest type.

so on.

*

*

* A forester who mistakes any such temporary forest growth for the original natural types of growth, thus failing to understand the natural evolution of the forest, will always have nature against him in all his operations, instead of being aided by her. * *The physical conditions of the situation then are the main factors which determine the whole character of a

*

*

forest type. Of these physical factors, climate undoubtedly has a marked influence upon plant life, if we compare vegetation of different latitudes. * * Soil, moisture in the ground, and topography, to which in mountain countries must be added altitude and exposure, are the main factors which determine the character of forest growth in a forest region, and, therefore, must be accepted as the basis for the division of the forest into natural types of growth. A natural forest type then is an aggregation of stands which may differ from each other in age, density and other secondary features, but have the same physical conditions of situation, like soil, topography, exposure, etc. * * * The relationship between the physical conditions of the situation and the character of growth upon it is so constant and characteristic that by the given physical conditions of a situation, like soil, topography, and so on, one can describe the general character of its forest, the predominant species, habit of trees, reproduction, undergrowth and, vice versa, by a given type of the forest growth one can describe the physical conditions of growth, soil, situation, etc. * A forest

* *

THE FOSSIL ARACHNIDA OF BOHEMIA. WE are indebted to Professor Dr. Anton Fritsch for another important contribution on the Permian and Cretaceous fauna of Bohemia entitled Neue Fische und Reptilien.' This takes the form of a quarto appendix to his previously published volumes, and is illustrated by nine plates. The Cretaceous forms described are new teleosts, plesiosaurs, mosasaurs and pterosaurs.

In 1904 there appeared from the pen and brush of this ardent paleontologist a fine monograph on the Paleozoic arachnida, consisting of eighty pages of text and fifteen plates. The conclusions reached in this monograph are most striking, especially as to the very great antiquity of modern forms. The author observes "If we examine the entire series of the forms described we must recognize that there are many which present no very striking differences from the Arachnida of to-day. They are to be regarded as the direct ancestors of families now existing in part as lateral branches which have later become extinct." This is true of members of six families described. The scorpions of the Silurian period show in their foot structure a primitive form suggesting that of the Crustacea whereas those of the Carboniferous and Permian formations exhibit close resemblance to the foot structure of the modern types.

H. F. O.

EXTENDED EXPLORATIONS OF THE ATMOSPHERE BY THE BLUE HILL OBSERVATORY.

ACCOUNTS of the first experiments in this country with ballons-sondes, for the purpose of ascertaining the meteorological conditions

at great heights above the American continent, appeared in SCIENCE, Vol. XXI., pp. 76-77 and 335. During the months of January, February and March, 1905, nine more ascents were made from St. Louis and every balloon but one was found and, with the attached instrument, was returned to Blue Hill in accordance with the instructions on each. Like the previous balloons, all of these fell within the eastern half of a circle having its center at St. Louis and a radius of 285 miles. The German expanding rubber-balloons, filled with hydrogen generated by the vitriolic process, were again employed, as were the French self-recording instruments, which gave at least partial records of barometric pressure and air-temperature in seven of the nine ascensions, although another record was obliterated by the finder. On January 25, when a high barometric pressure prevailed at the ground, a temperature of - 111° F. was recorded at the height of 48,700 feet, this being one of the lowest natural temperatures ever observed. The experiments last winter were conducted by Mr. Clayton, under the direction of Mr. Rotch, and their success induced Professor Langley, secretary of the Smithsonian Institution, to grant Mr. Rotch $1,000 from the Hodgkins Fund, in order to continue the experiments this summer at St. Louis. These, like the first, will be conducted by Mr. Fergusson, of the Blue Hill Observatory staff. Soundings of the atmosphere made at different seasons should reveal the annual variation of temperature at great heights above the American continent, which is at present unknown.

However, kites are not neglected at Blue Hill, for, besides the flights made there each month on the days fixed by an international committee, they are also being employed to ascertain the conditions above the Atlantic Ocean in the trade-wind region. Thus the investigation which was first proposed by Mr. Rotch in SCIENCE, Vol. XIV., pp. 412-413, and which has been persistently advocated by him since, is now in progress, and this was rendered possible through the cooperation of the well-known French meteorologist, M. L. Teisserenc de Bort, who placed his steamyacht at the disposal of Mr. Rotch, on condi

tion that the latter should share the expense of the cruise. Accordingly, on June 3, Mr. Clayton sailed from Boston for the Mediterranean on board the White Star steamer Romanic, equipped for raising self-recording instruments with kites, as was first done in 1901 by Messrs. Rotch and Sweetland, whose experiments on a voyage from Boston to Liverpool are described in SCIENCE, Vol. XIV., pp. 896-897. A despatch from Mr. Clayton, at Gibraltar, announced that flights had been made on six days and a mean height of 3,000 feet attained. The results of aerial soundings in the region of permanent high pressure around the Azores, and near the northern limit of the northeast trades, are expected to prove of special interest. At Gibraltar, Mr. Clayton is to embark on the Otaria, a yacht of 350 tons and capable of steaming eleven knots, which its owner has already employed for kite-flying in European inland waters. The boat will proceed south, touching at Madeira, Canary and Cape Verde Islands, and perhaps go as far as St. Paul, near the equator, returning by a more westerly course to the Azores, the whole voyage occupying about six weeks. On this route the northeast tradewinds and doldrums are traversed and the southeast trades entered. Should there be too little wind, either at the surface or higher up, the speed of the vessel will enable the kites to rise, and, should the wind at any time be too strong, by steaming with it the pull of the kites can be moderated. By this method it is hoped that all the strata up to a height of 15,000 feet or more will be penetrated, so that their condition as regards temperature, moisture and wind may be investigated. Besides determining the depth of the northeast tradewind, the supposed southwest, or return trade, which has only been observed on the Peak of Teneriffe, will be sought and its height above the ocean in different latitudes measured, but in case the kites do not reach a sufficient altitude, it is proposed to liberate small balloons from Madeira and observe their change of direction as they rise. Professor Hergesell, on board the Prince of Monaco's yacht, executed last summer a series of kiteflights in the region between Spain, the Canaries

and the Azores, without encountering the upper anti-trade, as was mentioned in SCIENCE, Vol. XXI., p. 464. The present expedition expects to make similar soundings in these and lower latitudes and will attempt to extend them to greater heights.

REGULATIONS GOVERNING THE SIXTH OF

INTERNATIONAL CONGRESS

APPLIED CHEMISTRY.

THE sixth International Congress of Applied Chemistry, under the patronage of His Majesty the King of Italy, will be held at Rome in the spring of 1906. The president of the committee of organization is Professor Emanuele Paterno, Via Panisperna, Rome, and the secretary, Professor Vittorio Villavecchia, Central Customs Laboratory, Rome. All who are interested in promoting the applications of chemistry are eligible for membership in the congress. Active members are those who signify their desire to be such to the general secretary either before the opening of the congress or during its session, and who send the subscription fee, twenty francs. Donating members comprise those persons or societies who contribute the sum of at least one hundred francs or lire. Those who give a thousand lire or more belong to the list of patrons.

The congress is divided into the following sections and subsections:

1. Analytical chemistry, apparatus and instruments-president, Pietro Spica, professor of pharmaceutical chemistry in the University of Padua.

2. Inorganic chemistry and industries related thereto-president, Luigi Gabba, professor of technical chemistry in the Higher Technical School, Milan.

3. Metallurgy and mining, explosives; (a) metallurgy and mining-president, Ettore Mattirolo, Geological Survey, Rome; (b) explosives-president, Cav. Guiseppe Ninci, colonel of artillery, superintendent of powder of Fontana Liri.

4. Organic chemistry and industries related thereto; (a) industry of the organic products -president, Giacomo Ciamician, professor of general chemistry in the University of Bo