-t-to 



METEOROLOGY. 



visible, but when sufficient water is present, con- 

 dense into fine drops and become a visible cloud. 



From a study of the records 1763 to 1897 K. 

 C. Mossman finds that, in London, snow is of most 

 frequent occurrence with north and east winds, and 

 least common with southwest winds. Hails, how- 

 over, occur most often with west, northwest, and 

 north winds. Gales are most frequent with west 

 nnd south winds. The greatest number of thunder- 

 storms, both in summer and winter, occur with 

 west winds, although the values in summer are also 

 high with east, southeast, and south winds. Ihe 

 greatest number of fogs are recorded on calm days, 

 and these are closely followed by days on which 

 the wind blows from the west. 



In observations on the transparency of haze dur- 

 in~ 1897, the Hon. F. A. Kollo Russell found that 

 the greatest clearness occurred with winds from 

 the westward, and the least clearness with winds 

 from the eastward. The highest mean visibility 

 was 24 miles with the west winds, and the lowest 

 mean visibility was 10.6 miles with northeast 

 winds. 



Miscellaneous. The average height of the me- 

 teorograph in Mr. A. Lawrence Rotch's kite-flying 

 experiments at Blue Hill, Mass., during August, 

 1898, was 7,800 feet, and on August 26 the meteoro- 

 graph was raised higher than ever before, its alti- 

 tude, determined trigonometrically, being 11,444 

 feet above Blue Hill, or 12,074 feet above the adja- 

 cent sea. The meteorograph was suspended from 

 the top kite, a Lamson aero-curve with 71 square 

 feet of lifting surface ; and 4 kites of the modified 

 Hargrave form, with a combined lifting surface of 

 149 square feet, aided to lift the wire, which was 

 5 miles long and weighed 75 pounds. The total 

 weight of the kites, lines, and apparatus in the air 

 was 112 pounds. The meteorograph left the ground 

 at. 10.40 A. M., attained its greatest height at 4.15 p. M., 

 and reached the ground at 8.40 P. M. It passed 

 tli rough cumulus clouds about three quarters of a 

 mile from the earth, and above them the air was 

 found to be very dry. The maximum wind veloc- 

 ity, 40 miles an hour, was reached at the height of 

 li,000 feet, while 100 feet higher the wind blew at 

 the rate of 32 miles an hour from the southwest. 

 On the hill at this time the wind was west, and its 

 velocity was 22 miles an hour. The temperature of 

 the air there was 72 when it was 38 in-the free air 

 11,444 feet above. 



A phenomenon, called Barisal gnns in India and 

 Mistpoefers in Europe, sounds like distant reports 

 of oannon or explosions, the causes of which are not 

 known, has received much attention of late years. 

 A book concerning them has been published by M. 

 K. Van den Broeck, in which hundreds of instances 

 are cited and described by the author or quoted 

 from authentic sources, in all of which an explana- 

 tion is sought. The sounds appear to be heard 

 most frequently near the sea, and in warm weather. 

 Communications made by Samuel W. Kain and 

 others to the "United States Monthly Weather Re- 

 view," show that the sounds are very frequent on 

 fine, calm summer days in the Bay of Fundy. 

 Prof. Cleveland Abbe has pointed out that there 

 i a resemblance between the sounds as they are de- 

 scribed and sounds made by drumfish in aquaria; 

 and that a large drnmfisii will give out a sound 

 that may be heard a long distance away. Prof. Abbe 

 suggests that the noises proceeding from the ocean 

 may have different characters ai)d origins. Some 

 may l>e due to the drumfish : others to breakers 

 flashing on rocky cliffs, whence heavy thuds spread 

 for many miles through the air and many miles 

 farther through the ocean ; others to the cracking of 

 rocks in ledges nearthe surface : and others, occasion- 

 ally, to genuine earthquakes occurring at the bottom 



of the neighboring ocean. The subject is one that 

 affords great scope for study. 



The second meeting of the International Aero- 

 nautical Congress, at Hamburg, March 31 to April 

 4. was largely occupied with the discussion of ques- 

 tions relating to the equipment of billions sondes, 

 or captive balloons, and manned balloons. The con- 

 gress recommended, among other things, that the 

 instrumental equipment of manned balloons should 

 be uniform, so far as possible, and that for each 

 ballon sonde an instrument should be provided to 

 serve as a basis of comparison with perfected in- 

 struments whose construction may change from 

 one ascent to another as improvements may be 

 attempted in them. Mr. A. Lawrence Rotch, of Blue 

 Hill Observatory, Mass., was present and made a 

 report on the use of kites at his observatory. The 

 chief of the United States Weather Bureau sent a 

 letter explaining the proposed use of kites to obtain 

 data for a daily synoptic weather chart over the 

 United States at the height of a mile or more. 

 Resolutions were passed favoring the use of kites at 

 suitable stations. It was announced that M. Teis- 

 serene de Bort was equipping a kite station at 

 Trappes, near Paris, after the model of Blue Hill, 

 and Gen. Rykatcheff stated that an anemograph of 

 his invention was being raised with Ilargrave kites 

 at St. Petersburg. 



A work on the meteorology of the Southern 

 Ocean, between the Cape of Good Hope and New 

 Zealand, was mentioned in the English Meteorolog- 

 ical Council for 1896 as having then been under 

 preparation ; and as no charts for that area had 

 been previously published by the office, the work 

 was expected to prove of much value. The results 

 of the weather forecasts continued to show a con- 

 siderable amount of success ; for those published in 

 the morning newspapers, a complete and partial 

 success of 81 per cent, was claimed for the year in 

 question, while for the special forecasts during the 

 hay harvest, the figures showed that 88 per cent, 

 were useful. A still greater success was claimed 

 for the warnings of storms, of which 91.5 per cent, 

 were justified. For the study of the climatology of 

 the British Isles, the office continued to subsidize a 

 small number of observatories of the highest class, 

 and maintain an intimate relationship with them, 

 and to supplement this information by observations 

 from a large number of voluntary stations. 



In an analysis of the duration of sunshine in 

 North America, presented to the German Meteoro- 

 logical Society at its triennial meeting in April, 

 Prof. Dr. Van Bebber stated that the amount of sun- 

 shine increases rapidly toward the south as in 

 Europe, and reaches a maximum in Arizona. As 

 in Europe, the mountains receive the most morning 

 sunshine, but. unlike Europe, the annual maximum 

 in America occurs in July, and in the South in 

 June. The speaker inferred that the characteristics 

 of the Northern and Southern people are t o be at- 

 tributed to climatic conditions, and are especially 

 affected by the deviation of sunshine. 



In an address to the Royal Meteorological So- 

 ciety, Mr. A. W. Clayden spoke of the extreme 

 value of photographic methods of recording the 

 movements of instruments, and of the real im- 

 portance of preserving photographic records of all 

 sorts of unusual meteorological phenomena, and 

 emphasized the necessity of companion photographs, 

 showing the same scene under normal conditions. 

 Having referred to some of the puzzles offered by 

 lightning photographs, the lecturer said that he hail 

 repeatedly found that a single discharge lasted 

 several seconds. He had several years before been 

 led to the proof that the "black" flashes shown in 

 photographs were merely a photographic phenom- 

 enon, but it is one that still remains unexplained. 





