49© 



NATURE 



[October 12, 191 1 



6o'7°, which is the highest for any similar period since 

 1841. The next means are 6o'6° in 1893, 6o'4° in 1868, 

 and 60' i° in 1865. These are the only summer six 

 months with the mean temperature at Greenwich 

 above 6o°, and there has not been any summer with 

 the nuan temperature above 58° since 1901. 



The following are the results for the several 

 months : — 



8 



The aggregate rainfall for the six summer months 

 is 869 inches, which is more than 3's inches less than 

 the average; there are several summers, comprised by 

 the six months April to September as dry. 



The mean temperature for the three summer 

 months June, July, and August is 66' i°, which is 

 4'9° in excess of the average for the past seventy 

 years; this is i° warmer than any previous summer. 

 The next warmest three summer months occurred in 

 1868, when the mean was 65' i°, and in both 1S59 

 and 1899 the mean was 65'o°. August was the 

 warmest summer month, the mean being i° higher 

 than in July. 



The warmest days during the summer were as fol- 

 lows : — 



Daily mean 

 Day Temperature n excess 



of average 



July 21 



Aug. 9 

 ,- 13 



Sept. 7 



There were in all during the summer seven days 

 with a temperature above 90 , and the only other 

 summer during the last seventy years with an equal 

 number of warm days is 1868. In 1876 there were 

 six days with the thermometer above 90 , whilst the 

 only other years with as many as four such warm days 

 were 1846, 1881, 1893, 1900, and 1906. There were 

 forty-five days during the summer, from April to 

 September, with the shade temperature at Greenwich 

 above 8o°, and previously the greatest number of such 

 warm days was forty in 1868. 



The absolute temperatures are very exceptional : — 

 9S'6° was recorded on July 22, which was the highest 

 previously recorded at any period of the summer since 

 1841, with the exception of 97" i° on July 15,1881, 

 and 96'6° on July 22, 1868. The maximum reading of 

 ioo° at Greenwich on August 9 is 3 higher than any 

 previous record at the Royal Observatory since 184 1. 

 On September S the shade temperature was 94' i°, 

 which is higher than any previous reading in Septem- 

 ber, and the mean of the maximum readings from 

 September 1 to 8 was warmer by 2 than the mean 

 for anv corresponding period since 1841. The mean 

 maximum temperature for August is Si'i , which is 

 the first occasion of the mean of the highest <lav read- 

 ings in August exceeding 8o°. 



The aggregate rainfall at Greenwich for June, July, 

 and August is 3*72 inches, which is 280 inches less 

 than the average. The only instances of a drier 

 summer are 3"65 inches in 1840, 2'qi inches in 1860, 

 and 2"50 inches in 1S64. The driest month of the 

 summer was July with 026 inch. 

 NO. 2l8q, VOT.. 87] 



The periods of absolute drought were twenty-three 

 days from July 1 to 23 and seventeen days lrom 

 August 2 to 18. 



There was an unusual amount of bright sunshine 

 throughout the summer — the aggregate duration in 

 the three months, June to August, was 819 hums, 

 which is 189 hours more than the average for the 

 last fifteen years. 



The black-bulb thermometer exposed to the sun's 

 rays exceeded 160 on July 22, August 4 and 9. 



Chas. Hauding. 



A VULCANOLOGICAL INSTITUTE. . 

 TN the Nuova Antologia of July 16, a copy of which 

 -^ has recently reached us, there is an interesting 

 article by Mr. Immanuel Friedlander, in which he 

 points out reasons which justify the attempt now 

 being made to establish an International Vulcano- 

 logical Institute. This is a matter to which we have 

 already referred (see Nature, April 6, 191 1, p. 180). 

 Among the many reasons why volcanoes should re- 

 ceive special attention is the fact that they bring 

 to the surface fused silicates and other materials 

 from the deeper parts of the crust of our earth which 

 otherwise we should not be able to reach. Two lines 

 of study are open to us. One is to investigate the 

 phenomena presented by a given volcano, whilst 

 the other is based upon the consideration of their 

 geographical and geological distribution. In connec- 

 tion with this distribution we are told that the 

 Atlantic and Pacific types of volcanoes differ in the 

 chemical characters of their products. Attention is 

 next directed to the fact that although many volcanoes 

 follow faults or lines of weakness in the crust of 

 the earth, examples are given of vents which seem 

 to be independent of such lines. 



The materials which have been erupted from 

 selected volcanoes are enumerated in some detail. 

 These fall under three heads, namely, materials which 

 are Basaltic, Andesitic, and Trachitic, the quantities 

 of silica in which are respectively 56, 60 and about 

 70 per cent. The volcanoes with the more acid lavas 

 are the most irregular and violent in their activity. 

 A curious feature connected with volcanic eruptions 

 is that the nature of the material ejected is not neces- 

 sarily constant. The first eruption from Panteleria 

 was basaltic, after which materials which were ande- 

 sitic together with acidic Liparites appeared. The 

 last efforts at this island, like the first, revealed 

 materials which are basic. 



From the softening of glassware and the ignition 

 of various materials, the temperature of the dust- 

 cloud which was shot out laterally to destroy 

 St. Pierre and its 30,000 inhabitants was estimated 

 at about 600 or 800 degrees. The needle-like pinnacle 

 which grew upwards from the crater of this mountain 

 is compared with the one which in 1909 grew in the 

 crater of Mount Tarumai in Yezo. 



These, together with many other curious appear- 

 ances and phenomena observed by the vulcanologist, 

 suggest that much remains open for investigation. 



One interesting section in the paper is a brief dis- 

 cussion of certain theories respecting the cause of 

 volcanic action. It is pointed out that water could not 

 pass to regions of heated rock through cracks or 

 fissures. Suess considers that the aqueous vapour 

 which escapes from volcanic vents represents water 

 which reaches the surface of the earth for the first 

 time, while Alfred Brun, of Geneva, denies the pre- 

 sence of water in volcanic eruptions. Stiibel, who 

 has worked amongst the volcanoes of Central 

 America, holds the view that each volcano derives its 

 materials from a special reservoir left in the crust 



