Oct. 27, 1887] 



NATURE 



617 



^^^pr. 



alt 



In the Bulletin of the Hungarian Geographical Society, vol. 

 XV. fasc. 7, will be found an interesting paper (abstracted in 

 French) on the struggle for existence among plants in the Hun- 

 garian Pusztas (steppes). 



To the Bulletin of the Belgian Geographical Society, No. 4, 

 1887, M. Louis Navez contributes an instructive paper on the 

 influence of the various geological formations in Belgium, 

 especially upon the people. M. Navez points out that Belgium 

 is specially favourable for such an investigation. In France and 

 Germany the great differences of altitude and latitude, and the 

 diversity of climate, determine phenomena often difficult to dis- 

 tinguish from those which are really due to geology, and are 

 therefore causes of error. In Belgium the differences of altitude, 

 of latitude, and of climate are not of so much importance. The 

 influence of the character of the soil is almost always pre- 

 ponderant, and is easily distinguished. One instance may be 

 given. The great quantity of lime which the Cretaceous soil of 

 the Geer valley contains gives to the straw of the cereals a 

 special suppleness, strength, and whiteness. From this straw 

 are manufactured plaits which have a large sale, and in Paris are 

 ranked next to the straw of Italy for ladies' bonnets. This 

 manufacture is worth from four to five million francs yearly, 

 On the other hand, the absence of calcareous salts in the ground 

 traversed by the feeders of the Lys, render that river eminently 

 suited for the cleansing of flax ; hence the fame of the cloths of 

 Flanders. M, Navez believes that the facts he brings together 

 prove that the geological construction of the ground is one of the 

 factors that limit the free will of man and have an active influ- 

 ence on communities. 



In Dr. Oscar Baumann's paper on Fernando Po, in No. ix, of 

 Peterviann^ s Mitteilungen, the author states that the volcanic 

 group of which the island is a member, forms a line running 

 south-west from the Cameroons, and may be regarded as the 

 result of an eruptive fissure, which on the one side extends from 

 the Cameroons to the island of Annobon, and on the other 

 appears to find in the Rumbi Mountains a continuation into the 

 heart of Africa. The northern half of the island is covered 

 almost entirely by the huge volcanic peak of 0-Wassa (Clarence 

 Peak). After careful estimation he gives the summit a height of 

 9350 feet. The volcano may be regarded as extinct, the fire and 

 clouds of smoke seen at times on the summit being easily ex- 

 plained by the annual burning of the grass. The crater on the 

 top of the mountain is 515 feet in depth, and is inclosed by gray 

 disintegrated walls of basalt. On the thickly wooded and almost 

 impassable slopes are many subsidiary craters. The basaltic rock 



f the east coast is being gradually crumbled away by the sea, 



hile along the west coast the land is gaining on the sea. The 

 physical geography of the southern half of the island is determined 

 by the mountain range of the "Cordillera of Fernando Po," 

 which in two chains connected by a pass runs practically east and 



est. These chains culminate in several summits, which have 

 volcanic character only on account of their basaltic composi- 



lon. In the south of the island, and apparently quite inde- 

 ndent of the Cordillera, there rises a lofty volcanic mass. On 

 e top of one cone-shaped peak, precipitous on all sides, there 

 tends a flat basin surrounded by a circle of hills. This the 



uthor supposes to be the remains of a large crater. 



M. A. J. Wauters writes a long article in the new number of 

 e Mouvement Geographique to prove that Lake Muta-Nzige, 

 e somewhat problematical lake to the south of Albert Nyanza, 

 elongs to the Congo system, and not to that of the Nile. The 



altitudes and other data which M. Wauters has on which to base 

 s conjecture are of the scantiest, and extremely doubtful. It 

 icms to us that such conjectural arm-chair geography is a use- 

 waste of time and space. The question of the relation 

 tween the Muta-Nzige and the Albert Nyanza can only be 

 Ived by actual exploration. By this time no doubt it has been 



solved either by Emin Pasha or Stanley, and M. Wauters might 



therefore put the valuable space of his small journal to a much 



more profitable use. 



METEOROLOGICAL NOTES. 



The Hydrographer to the Admiralty has issued a circular 

 stating that the United States Government has given notice that 

 from September i, 1887, the following storm signals (consisting 

 of day signals of two kinds, also night signals), would be shown 



on the shores of the Atlantic Ocean, Gulf of Mexico, and Great 

 Lakes, as storm conditions may demand, taking into considera- 

 tion the fact that westerly winds of high velocity with clearing 

 weather are less dangerous than those from easterly quarters 

 with freezing weather: (l) cautionary signal, a yellow flag with 

 white centre, will indicate the winds expected are not so severe 

 but that well-found and seaworthy vessels can meet them with- 

 out great danger ; (2) storm signal (now in use), a red flag with 

 black centre, will indicate that the storm is expected to be of 

 more marked violence. In order to afford as exact information 

 as possible regarding the relative positions of the storm and the 

 winds expected, two pendants will be displayed : a red pendant 

 will indicate easterly winds, from north-east to south inclusive, 

 and that the storm centre is approaching ; a white pendant will 

 indicate westerly winds, from north to south-west inclusive, and 

 that the storm centre has passed. Whilst it is intended that the 

 pendant shall indicate positively only whether the winds will be 

 easterly or westerly, yet in order to give still more definite in- 

 formation, the red or easterly pendant will be hoisted alxjve the 

 cautionary or storm signal, for winds from the north-east 

 quadrant, and below for winds from the south-east quadrant. 

 Also, the white or westerly pendant will be hoisted above the 

 cautionary or storm signal for winds from the north-west 

 quadrant, and below for winds from the south-west quadrant. 

 Because of the difliculty of varying night signals, they will not 

 distinctly show the force, but indicate the direction of the wind 

 only ; a red light far easterly winds, and a red and white light 

 for westerly winds. 



The Pilot Chart of the North Atlantic Ocean, issued by the 

 Hydrographic Office at Washington for the month of September, 

 includes a valuable article on the law of storms, considered with 

 special reference to the approaching season of West Indian 

 hurricanes. The article is accompanied by two diagrams 

 illustrating (i) the circulation of the wind in a tropical cyclone 

 in the northern hemisphere, showing clearly how the wind is 

 drawn in towards the centre of low barometer, and its direction 

 at any point ; and (2) a diagram for practical use in finding a 

 ship's position relatively to the centre of the hurricane, by means 

 of the direction of the wind and fall of the barometer. The 

 circles in this diagram are normal isobars, and represent the rate 

 at which the barometer falls as the centre of the storm is 

 approached, so far as our latest knowledge of cyclones can be 

 safely used as a general guide. Full directions are given for the 

 practical use of these diagrams. The Pilot Charts contain 

 frequent extracts from ships' logs, as to the great value of the 

 use of oil in heavy seas, and the Hydrographic Office considers 

 that the testimony is so conclusive that its use is now recognized 

 by every commercial nation. The Charts contain information 

 about winds, currents, fog, and the position of dangerous 

 derelicts, and their speedy dissemination must prove to be of 

 great utility to the maritime community generally. 



The Annalen der Hydrographie tmd maritimen Meteorologie 

 for August contains a graphical representation of the distribution 

 of rainfall in the Atlantic and Indian Oceans, compiled by Dr. 

 W. Koppen from materials at the disposal of the Deutsche 

 Seewarte and all other available sources. The latitude is shown 

 in the vertical, and the months in the horizontal direction ; each 

 point of the area of the diagram therefore indicates a definite 

 time of the year, and a definite distance from the equator, and 

 the curves show the equal percentages of days of rainfall. The 

 diagrams are explained in the text, and show the relatively 

 large rainfall frequency in the higher latitudes of the North 

 Atlantic in all seasons, but especially during winter ; further south- 

 wards, towards the region of the trade-winds, all months become 

 drier, but north of the tropics rain falls on an average once in 

 every 5-10 days. In the South Atlantic the conditions are 

 more complicated. From o°-5'' S. autumn rains are prevalent, 

 and from S^-h" S. the winter rainfall maximum is prominent. 

 In the Indian Ocean the equatorial rain-belt is ^ considerably 

 widened, especially on the southern side. From 2° N. to 12° S. 

 the rainfall frequency does not fall below 50 per cent, in any 

 month, and from June to October it exceeds 70 per cent. Between 

 10° and 12° S., and also from 25°-3o'' S. the spring-time is 

 driest ; while from 33° S. the rainfall increases rapidly in winter 

 and spring. South of 40° S. it rains eight days out of ten during 

 July and August. 



Symons's Monthly Meteorological Magazine for September 

 contains interesting articles on the deficiency of rainfall this 

 year and on the definition of drought. From a comparison 



