METEOROLOGY. 



489 



surface. In the Danubian basin the typical fur- 

 nace, even in prehistoric times, was a small shaft 

 furnace built in a bank of earth. Evidences were 

 adduced by the author indicating that the intro- 

 duction of the extraction of iron into Europe 

 took place along two lines one from Egypt to 

 Etruria, and the other from Asia by the north 

 of the Euxine to the Danube, and thence to cen- 

 tral Europe. In the furnaces of either origin 

 wrought iron, sometimes of a steely nature, was 

 produced direct from the ores. 



METEOROLOGY. Temperature. Observa- 

 tions on the temperature of the free air and its 

 variations were made every month from April, 

 1898, till the publication of the report by means 

 of 90 unmanned balloons sent up from the ob- 

 servatory of M. Teisserenc de Bort at Trappes, 

 France. Seven of the ascents exceeded 14,000 

 metres, 24 went above 13,000 metres, and 53 at- 

 tained a height of 9,000 metres. The results were 

 deduced from the discussion of the observations 

 that the temperature at various heights presents 

 during the course of the year important varia- 

 tions and greater ones than had been admitted 

 from older series of observations made in manned 

 balloons; that the temperature of C. is found 

 at very different altitudes, varying from the level 

 of the ground in winter to above 4,000 metres 

 in summer; that the isotherm of 25 C. is met 

 with at the height of about 3,000 metres in win- 

 ter and above 7,000 metres in summer in Sep- 

 tember it was observed even above 8,000 metres; 

 that the isotherm of 40 C. was several times 

 found as low as 6,000 metres, and is generally 

 met with about 9,000 metres and even higher 

 toward the end of summer; and that the tempera- 

 ture of 50 C. has never been recorded below 

 8,000 metres. There appears to be a marked 

 tendency to an annual variation of temperature 

 even up to 10,000 metres, the maximum being 

 about the end of summer and the minimum near 

 the end of winter. The observations recorded in 

 a table appended to M. De Bort's paper do not 

 show such a rapid variability with height as has 

 generally been supposed; its rate appears, fur- 

 ther, to be modified according to the type of the 

 weather. 



In an account given in the British Association 

 of the progress made during the preceding year 

 at Blue Hill, Mass., in the exploration of the air 

 with kites, Mr. A. L. Rotch said that the Har- 

 grave kite with curved surfaces had been found 

 more satisfactory than any other form, and that 

 the meteorograph records temperature, humidity, 

 height, and wind. Temperature is found to de- 

 crease at first with elevation, and afterward to 

 increase again. The heights attained were, on 

 the average, greater than in previous years. The 

 United States Government had arranged for daily 

 simultaneous observations at two heights in the 

 case of a number of stations, using the kite for 

 the high-level observations. The results were 

 not quite satisfactory, because kites could not 

 be sent up on some days, and it was suggested 

 that on such occasions a captive balloon be em- 

 ployed. In the discussion of the paper Prof. 

 Thomson said he hoped that the variation of at- 

 mospheric potential w r ould be investigated by 

 means of kites. 



From studies of 51 mild winters experienced in 

 Berlin during the last one hundred and eighty 

 years Dr. C. Hellmann deduces the conclusions 

 that such winters hardly ever occur singly, but in 

 groups of two or three; that they are usually 

 of long duration, from November to February 

 or March. Severe and long late winters (till 

 February or March) seldom occur after mild mid- 



winters. In mild midwinters the greatest varia- 

 tions of temperature usually occur in January. 

 After a very mild winter a warm summer is more 

 probable than after a winter which is only mod- 

 erately mild. Dr. Hellmann pleads for synoptic 

 charts for the whole globe at least for short in- 

 tervals if longer periods can not be undertaken. 



A review of extremes of temperature published 

 in Symon's Meteorological Maga/ine gives the 

 highest yearly isotherms as 85 F., a degree which 

 is recorded in three areas the largest in central 

 Africa south of latitude 18 north; the other in 

 central India, latitude 15 north; and in the 

 northern part of South Australia. The absolute 

 range of shade temperature in the northern hemi- 

 sphere, and probably in the world, is 217.8, 

 a figure which is deduced from the absolute maxi- 

 mum of 127.4 in Algeria on July 17, 1879, and 

 the absolute minimum of 90.4 at Werkojansk, 

 Siberia, Jan. 15, 1885. The hottest region is on 

 the southwestern coast of Persia, where the ther- 

 mometer has not been known to fall lower than 

 100 F., night or day, for forty consecutive days 

 during July and August, and often to reach 128 

 in the afternoon. Among the highest shade tem- 

 peratures recorded are one at night during the 

 Italian occupation of Massowah, when the ther- 

 mometer is said to have recorded 122 F. Tem- 

 peratures above 120 F. are occasionally met with 

 in India; 121.5 was recorded at Dera-Ishmail- 

 Khan (latitude 32 north) in 1882, and 126 at 

 Bhag (latitude 29 north) in 1859. At Wilcannia, 

 on the Darling river, New South Wales, shade 

 temperatures varying from 107 F. to 129 F. 

 were recorded on each day from Jan. 1 to Jan. 

 24 in 1896. Among the low temperatures in ad- 

 dition to the extremes already mentioned is 

 63.1 F. at Poplar river, North America. The 

 extremes in or near London for one hundred and 

 four years were 97.1 F. in July, 1891, and 4 in 

 December, 1796, and January, 1841. 



Clouds. Simultaneous observations by a num- 

 ber of meteorological services, to continue at 

 least one year, were begun in 1896 to determine 

 the height and motion of the ten standard types 

 of clouds which have been defined by. the Inter- 

 national Cloud Committee. The part of this 

 work undertaken by the Weather Bureau of 

 the United States has been completed, and will 

 be published in the annual report of the bureau 

 for 1898-'99. This work includes observations 

 made by two theodolites placed at the ends of 

 a long base line, giving the absolute height, 

 velocity, and direction of motion of individual 

 clouds at Washington, and those made with 

 nephoscopes at 14 stations over the districts 

 east of the Rocky mountains, giving the relative 

 velocity and direction of motion. The discus- 

 sion of the data will show the distribution and 

 average height of each type of cloud for every 

 day in the year, and the depth of the zone or 

 horizontal belt in which each type may occur. 

 Determinations have been made of the direction 

 and velocities of the horizontal motions of the 

 air in each of the eight principal levels on all 

 sides of the areas of high and low pressures as 

 they move over the United States. 



The results of the measurement of cloud heights 

 by Mr. A. W. Clayden by means of two cameras 

 200 feet apart show the existence of greater 

 heights of clouds in hot weather under thunder- 

 storm conditions. In such circumstances clouds 

 may occur at five or six different levels, extending 

 as high as 90,000 feet. The margins of the alto- 

 cumulus and cirro-cumulus clouds are much 

 higher under those conditions than the generally 

 accepted means. A rise of cloud plains takes 



