METEOROLOGY. 



471 



from nearly every country in the world. The 

 Tinted Stales was represented by .Mr. Mutch, of 

 Blue Hill Observatory, Massachusetts, and Mr. .1. 

 . of the Hydrographie Ollicc. Washington. 

 M. Maseart. of France, presided. The resolutions 

 adopted concerned the provision of thermometer 

 shelters and uniformity in the models of them; the 

 addition of symbols to those already adopted for 

 distant and sheet lightning, for lightning and 

 thunder, and the classification of showers with re- 

 spect to these phenomena : recommended observa- 

 tion, in the present condition of the science, of the 

 duration of sunlight rather than its intensity: and 

 advised a uniform height of a metre and a half for 

 pluviometers. A committee report on the adapta- 

 tion of aeronautics to meteorology recognized its 

 great importance, and advised that scientific ascen- 

 sions be encouraged and multiplied ; that whether 

 with free or fixed balloons they be made simultane- 

 ously from different stations: that while specific in- 

 struments could not at present be recommended, 

 those employed in simultaneous ascensions be iden- 

 tical in character; that as prompt publication as 

 possible is important of the actual observations, es- 

 pecially of those made in simultaneous ascensions; 

 that observations in captive balloons be executed 

 regularly : and that " in view of the satisfactory re- 

 sults which kites carrying registering instruments 

 to the height of 2,000 metres have given at Blue 

 Hill, it is desirable that like researches be under- 

 taken elsewhere." Another committee reported that 

 an international organization for the observation of 

 clouds had been effected, in which nearly all the 

 countries participated, and observations either di- 

 rect or indirect and photo-grammetrical were now 

 made in Sweden. Norway. Russia. France. Prussia, 

 and the United States, and photogrammetric sta- 

 tions would shortly be installed in Hungary and 

 India, and at Manilla. Batavia. and Sydney. 



An historical investigation made by Mr. II. C. 

 Russell, of New South Wales, of the theory of a 

 weather cycle of nineteen years, has resulted' in an 

 apparent confirmation of it. The investigation was 

 made by means of a comparison of the notices 

 of droughts that are found in the records of recent 

 times, and in modern and ancient times as far back 

 as they occur. Droughts are selected rather than 

 any other special feature because, their effects being 

 more intense, they are more likely to receive atten- 

 tion. A weak point in the evidence adduced by 

 the author is that history has not kept a regular 

 and continuous record of droughts, but has re- 

 corded them only when they become very promi- 

 nent. It has. on the other hand, the strong point 

 that all the data that history gives us is in favor of 

 the nineteen years' cycle. First, Mr. Russell finds 

 that during the whole period from the foundation 

 of the colony of New South Wales to 1896 one 

 hundred and eight years the most pronounced 

 droughts have recurred regularly every nineteen 

 years. Indian droughts seem to have coincided with 

 Australian ones in many instances. Examining 

 historical records previous to the Australian era, 

 the author finds that of 52 repetitions of droughts 

 possible on his theory since A. D. 900. 44 are men- 

 tioned as having occurred at various places on the 

 earth, and all at dates that fit well into the nine- 

 teen-year period. In the years before Christ, men- 

 tions of 20 droughts are found, all of which, with 

 one exception, occurred at intervals which are mul- 

 tiples of nineteen years. Besides these "great 

 droughts" another set of dry periods, more intense 

 and relatively shorter than the first series, were 

 found, falling regularly between pairs of the more 

 extensive ones, and also marking a nineteen-year 

 period. Further, 69 records of falls of red dust 

 " obviously a proof of drought somewhere, other- 



wise the dust could not rise." and pro< fs of 

 drought entirely apart from the others, ami 

 corded not as droughts but a> marvel-," all of 

 which "fit into the nineteen years' cycle." The au- 

 thor is continuing his investigation, and is prepar- 

 ing a paper in which he will try to show a connec- 

 tion between this weather cycle ami the lumar cycle 

 o( nineteen years. 



Prof. Cleveland Abbe has shown that geology 

 and agriculture, as well as meteorology, ate inter- 

 ested in the part played by the small quantity ol 

 carbonic-acid gas that exists in the atmosphere. 

 The leaves absorb and eliminate a portion ; the fall- 

 ing raindrops and the surface water of the ocean 

 absorb another portion ; it is exhaled from the 

 lungs, and given off in still greater quantities from 

 every burning substance. It may accumulate tem- 

 porarily in some regions, but slow diffusion and 

 swifter winds carry it away. It ought to diminish 

 as we ascend above the earth's surface, but the 

 rapidly rising and falling currents of air tend 

 to preserve a fairly uniform mixture very much as 

 they do in the case of water vapor. Evidently 

 there is a general balance between the production 

 and absorption of carbonic-acid gas, so that, like 

 the temperature of the air and the quantity of rain 

 or any other meteorological element, we find no 

 great progressive secular increase or diminution. 



Some interesting general conclusions are drawn 

 by Prof. Ramann from his researches on the rich- 

 ness of the water content of wooded soils. The ex- 

 periments were prosecuted at Eberswalde in Is'.fo. 

 when the spring was dry. on a sandy, slightly 

 clayey soil, with a dry subsoil. Compact >oils 

 proved to contain less moisture than cultivated 

 soils ; and soils which had been bare for a long 

 time were no exceptions to the rule. The dry 

 periods of the spring, till the beginning of the 

 vegetal activity of the trees and the opening of the 

 leaves, exercised no sensible influence on the rich- 

 ness in water of the soils of a coir, pact mass. After 

 the appearance of foliage, there was first a rapid 

 and then a slower, continuous drying out of the 

 deeper strata of the soil. On tilled lands kept clear 

 of weeds the upper strata were not dried below ~> 

 or at most 10 centimetres, while the deeper strata 

 suffered only an insignificant loss of water. Dur- 

 ing the dry period of the spring of 1893 the water 

 content of the soil fell for a notable depth to half, 

 and in many cases to a third of the normal. These 

 observations are of course valid only as to soils 

 like those on which they were made, and other re- 

 sults might be obtained with other, especially with 

 clay soils. 



Some noteworthy facts in the audibility of fog 

 signals have been commented upon by Prof. H. A. 

 Hazen in the " American Meteorological Journal." 

 A passenger steamer had grounded on Great Gull 

 island about 5,000 feet due west of a fog signal 

 which was sounding at the time. The siren had 

 been heard to a distance of 20 miles under favor- 

 able circumstances, but the captain of another 

 steamer, which approached the island from the west 

 at the time of the accident, said that his lookout 

 was not able to hear any sounds as they approached 

 the island, whereas, after passing, the whistle could 

 be plainly heard. 



The most prominent feature of the climate as 

 shown in the record of results of meteorological 

 ob-ervations at Boroma. on the Zambesi river, in 

 16 = south latitude, is the contrast between the dry 

 and wet seasons. The approach of the rainy season 

 is announced by lightning in the north and north- 

 diiring October; rain begins in November, 

 and continues, on and off. for about five months: 

 hail also occasionally occurs during thunderstorms. 

 The dry season begins in April, and till the follow- 



