MISCELLANY. 



763 



of restoring their blighted vineyards. From 

 a few rooted plants selected by Prof. Riley, 

 and sent over four years ago to Gaston Ba- 

 zille, then President of the Central Agricult- 

 ural Society of Herault, the demand in- 

 creased each year, until in 1874 it reached 

 many millions, and we have the curious 

 spectacle of a large exportation of Ameri- 

 can vines to a country that has hitherto de- 

 spised them as unworthy of culture. We 

 see from some of the French papers that 

 Prof. Riley has this summer revisited the 

 south of France, and that he has found the 

 American vines flourishing in the midst of 

 the dying and dead French vines, and in the 

 order of the varieties recommended four 

 years ago. To testify their appreciation of 

 his services, the Central Society of Agricult- 

 ure of the department of Herault held an 

 extraordinary session at MontpeUier, and 

 gave a grand banquet at Palavas, in his 

 honor. 



Formation of Dail in the Spray of To- 

 semite Faili The Americmi Journal of Sci- 

 ence for September contains an interesting 

 article, by Prof Brewer, on the formation of 

 hail in the spray of the Upper Yosemite 

 Fall, as observed by himself on the 14th of 

 April last. This magnificent fall is 1,550 

 feet high, and at the time, the stream being 

 swollen by rains and melting snow, leaped 

 clear from the rocks into the air and was 

 soon torn into spray. "It seemed," says 

 the professor, " as mobile as smoke, and 

 assumed new varieties of outlines each in- 

 stant, so light and airy that it seemed as 

 easily swayed by wind as lace, yet it struck 

 with deafening thunder. The concussion 

 was perceptible through the granite for 

 some distance." The discbarge of water 

 was estimated at 250 to 300 cubic feet each 

 second. 



The water in winter falls behind a great 

 cone of ice which forms from 100 to 200 

 feet in thickness, and emerging beneath the 

 ice a grand arch is formed like that in the 

 glacier at Mont Blanc, whence the Arveiron 

 flows. Standing at the foot of this upper 

 fall, a thousand feet above the bottom of the 

 valley. Prof. Brewer and his companions felt, 

 in the violent tempest of spray, ice-pellets 

 or hail which stung their hands and faces 

 like shot. They fell in considerable quan- 



tity, rapidly melting, for the sun shone full 

 on the fall, and the rocks around reflected 

 the heat. The diameter of some of the 

 pellets was estimated at one-tentii of an 

 inch. 



Here we have the spray of the water-fall 

 condensed and frozen into hail. The pro- 

 cess by which this may occur is clearly 

 stated by Prof Brewer. 



The water, supplied from melting snow, 

 plunges over the cliflF at just about the tem- 

 perature of freezing. " In the fall it appears 

 to be 'atomized' for 1,200 or 1,400 feet of 

 its descent. A great volume of air is drawn 

 into this falling mass along its whole course, 

 the sheet spreading as it descends. The 

 quantity of air is so great that it pours out- 

 ward on the bottom of the valley and is very 

 perceptible as a cool current more than a 

 mile distant from the base of the upper fall. 

 The air as sucked into the fall is immedi- 

 ately cooled to 32 by the ice-cold water. 

 As it passes in, it is very dry, and the rapid 

 saturation within the sheet is sufficient to 

 freeze a portion of the drops." 



Distribntion of Temperature on the So- 

 lar Disk. From the researches of Prof 

 Langley, referred to last month in the ab- 

 stract of Secchi's observations on sun-spots, 

 it appears that, though the nucleus of a spot 

 is much cooler than the surface surrounding 

 it, there is no great difference of tempera- 

 ture between it and the photosphere near 

 the sun's limb, though the difference in 

 brightness is so considerable. In fact, Mr. 

 Langley has shown that the relatively black 

 nucleus actually radiates more heat than 

 the bright photosphere quite close to the 

 limb. Following up this discovery, he has 

 shown that the absorption of light, both in 

 the case of a spot, and of the parts of the 

 sun's surface near the limb, is not accom- 

 panied by a corresponding absorption of all 

 the heat-rays (invisible as well as visible), 

 so that, taking Sir W. Herschel's estimate 

 of the brightness of the nucleus as xfotj of 

 that of the photosphere, Mr. Langley finds 

 that we receive from a spot fifty times as 

 much heat as light, and a similar conclusion 

 is arrived at with reference to the surface 

 near the limb. On comparing the equato- 

 rial and polar regions, no appreciable differ- 

 ence was observed in the heat received. 



