Nov. 13, 1884] 



NA TURE 



41 



accepted n professorship at the Gottingen University, we are 

 informed that the celebrated astronomer will, in consequence of 

 the generous offer made to him by the King of Sweden, remain 

 in his native country. 



Prof. F. E. Nipher finds, according to Science, from data 

 taken from Dr. Engelmann's observations at St. Louis, Mo., 

 lasting over a period of forty-seven years, that the duration of 

 maximum rain^ is inversely proportional to the violence, or that 

 the product of violence into duration is constant. This constant 

 is the amount of water which may fall in a continuous rain, and 

 is, for Dr. Engelmann's series of half a century, about 5 inches. 

 A rain of 5 inches per hour may last one hour. A rain of 4 

 inches per hour may last an hour and a quarter ; and such a rain 

 Dr. Engelmann observed. A rain of 2h inches per hour may 

 last two hours, and several such rains were observed. A rain of 

 l inch per hour may last 5 hours. Each of these cases would 

 be a 5-inch rain. For a longer period of time than fifty years it 

 is likely that greater rains than 5 inches may be observed. The 

 same is to be said if observation, are to be taken over a wider 

 area of country. In fact, a rain of 6 inches in three hours 

 occurred near Cuba, Mo., some years since. This would 

 increase the value of the constant from five to six, but 

 otherwise the relation will probably remain unchanged. 

 The importance of this law, Science points out, is very great in 

 e igineering, where'the capacity of sewers, culverts, and bridges 

 must be such as to carry the water. A more general investiga- 

 tion which Prof. Nipher is now making will determine the rela- 

 tion between the violence, duration, and frequency not only of 

 maximum but of all rains. This work, when completed, will 

 enable an engineer to construct the water-ways of bridges of 

 such a capacity that they will probably stand a definite number 

 of years before the}' are washed away. This number of years 

 will be so determined that the interest on the invested capital 

 during the probable life of the bridge will equal the possible 

 damage when the destructive flood comes which the engineer 

 determines shall destroy his work. The running expense of 

 maintaining the bridge is then the least possible. 



In the October number of the American Journal 0/ Science 

 Mr. Lewis discusses the validity of observations on supposed 

 glacial action at eleven points in Pennsylvania south of the ter- 

 minal moraine, all of which he has visited. He concludes that 

 they are all non-glacial, some being simple water-worn gravels, 

 others being ice-rafted boulders, while the scratches reported in 

 two localities are pronounced to be plant-fossils. The glacial 

 action reported in Virginia needs, it is said, similar re- 

 examination. 



The Meudon balloon made its third trial trip last Saturday. 

 Starting at 12.15 noon, when a slight south-west breeze was 

 blowing, it drifted in the direction of the Boulogne racecourse, 

 and after arriving in the vicinity of that place, a distance of 

 about a mile from its starting-point, obeying the motive power 

 controlling its movement, it retraced its journey and alighted at 

 the place from which it had ascended at one o'clock, having 

 thus taken three-quarters of an hour to finish its trip of two 

 miles altogether, going and coming. It is said, however, that 

 the motive power of the voltaic elements was not quite so 

 efficient as had been anticipated. 



At the last meeting of the Geographical Society of Hamburg, 

 Dr. Sievers gave a short sketch of a journey of a year's duration 

 which he intends making in the Cordilleras of Merida in Vene- 

 zuela. Geographical investigation has, so far, not touched this 

 region. Humboldt travelled through the eastern part from 

 Cumana to Caracas, the llanos of Caracas and Calabozo, and 

 the districts in the Upper Orinoco, but he did not visit the 

 Cordillera region of Merida. Later travellers also, including 



Godazzi, whose work was otherwise thorough, did not reach the 

 place. Dr. Sievers will examine the region geologically, and 

 obtain as many measurements of heights as possible. 



The report of a journey from Seul, the capital of Corea, to 

 Songdo, by Mr. Aston, a consular official in Corea, has been 

 published. The difficulties of travel in the country appear to 

 have been much exaggerated ; the people are friendly to 

 strangers, and the discomforts are not greater than in China. 



According to a telegram from Calcutta, Mr. Griesbach, the 

 geologist with the Afghan Boundary Commission, describes the 

 route between Quetta and the Helmund as presenting features 

 very similar to those in the Pishin valley and Candahar, namely, 

 a system of precipitous, deeply eroded ridges, extending from 

 north and south to north-east and south-west. Extensive post- 

 Tertiary deposits fill the intervening valleys. The south-west 

 extremity of the Ghazarband range is composed of sandstone 

 shales and grits of the Flysch facies of Eocene rocks. A series 

 of low hills and valleys stretch between Canjpai and Nushki, 

 which from their composition appear to be merely continuations 

 of the Kojah Amran range, but near Galiahah the formation is 

 distinctly younger, the epoch being mostly 1 rap-rock, which in 

 places bursts through the Cretaceous limestone overlying it, and 

 locally converts it into white marble. 



Not the least valuable of the many excellent reports published 

 in the course of the year by the Chinese Customs department is 

 that of the medical officers on the health of the various ports at 

 which they are stationed. These gentlemen deal frequently 

 with subjects of wider interest than the sanitary condition and 

 health of certain limited portions of the Chinese Empire. Thus 

 in the last reports, Dr. Macgowan, of Wenchow, gives an 

 account of the cholera epidemic which visited China last year. 

 He states, on the authority of a native author, that Indian or 

 Asiatic cholera first made its appearance in China in 1S21, 

 medical tradition attributing its origin to the Straits of Malacca, 

 whence it was brought to Fokhien in a junk. It subsequently 

 spread southward to Canton, and from thence to other provinces. 

 In 1825 a great outbreak occurred at Ch'un-Ching. on the 

 Vangtsze, and thence the disease travelled slowly northward, 

 visiting Corea and Japan, where it became extremely virulent. It 

 has since been endemic in China, sometimes becoming epidemic, 

 occasionally extending over the whole of Eastern Asia, and at 

 other times confining itself to a province or part of a province. 

 Dr. Macgowan states that the native doctors treated the disease 

 as common cholera, and did not cure one in a hundred ; and he 

 concludes that Indian cholera in China differs from the common 

 cholera of the country only in its epidemic character, the former 

 being migratory, the latter stationary. 



In the Archivesdes Sciences physiques :t nalurelles, Prof. Forel 

 of Morges has a paper on the solar corona of the spring of 

 18S4, of which the following is a summary. In Switzerland, 

 in the course of the present year, has been observed an extra- 

 ordinary optical phenomenon consisting of a reddish corona of 

 large diameter surrounding the disk of the sun, as well as of a 

 reddish tint on the white clouds. This corona has been visible 

 since the beginning of the year, and during the months of July 

 and August it was constantly seen. Visible from high altitudes 

 whenever the sky was clear, it was generally lost lower down, 

 hidden probably by the light from lower layers of dust in the 

 atmosphere. The corona is probably occasioned by dust 

 settling in the higher layers of the atmosphere where they 

 are protected from meteorological variations of the lower layers. 

 This dust would be of uniform dimensions, and of a meaa 

 diameter of about 0003 mm. In the absence of any other ex- 

 planation, M. Forel refers this phenomenon to the brilliant 

 crepuscular illuminations of last winter, and attributes these 



