NOTES. ' 619 



artificial production of rain by means of electricity have just been carried out in 

 Jai^an. Waves of electricity directed skyward under a system somewhat similar to 

 that upon which wireless telegraphy is based have' resulted in atmospheric disturb- 

 ances of far greater area than any ever artificially produced through the medium of 

 detonating explosives in the upper air strata. The probability of achieving greater 

 success in rain making through the means of electricity than by the use of explosives 

 has been urged by scientists for several years. This attempt by the Japanese, how- 

 ever, is the first practical effort to prove the truth of the theory. It was attended by 

 conspicuous success. Operations were commenced at 11 in the evening, but there 

 was no sign of atmospheric change until 9 o'clock next morning, when a cluster of 

 clouds was observed over the hill on which the ex])eriment was held. At length 

 rain began to fall, followed by a second fall at 11 a. m., and afterwards a third, fourth, 

 and fifth, the last being about 9.80 in the evening. The area upon which the rain 

 fell extended over many miles. 



The Nile Dam at Assuan.— The great irrigation dam at Assuan was opened with 

 much ceremony in December last. This dam, the largest of its kind ever constructed, 

 will, according to Nature, hold up the waters of the Nile for a distance of 147 miles. 

 It is a mile and a quarter long, constructed of solid granite and cement upon a natural 

 bed of granite, over which the river flows. It is 82 ft. high, 80 ft. thick at the base, 

 and 24 ft. at the top. There are 140 lower openings, 23J ft. high by 6 ft. wide, and 

 40 upper openings, provided with doors so hung and l)alanced that they can be 

 raised and lowered with little labor. Through these openings the Nile water will 

 flow in time of flood, carrying with it the sediment that may have accumulated when 

 the gates were closed. As the flood waters diminish the gates will be closed and 

 the water impounded, to be taken out in such quantities as are required for irriga- 

 tion during the summer months. For the accommodation of navigation a canal 50 

 ft. wide and 1 mile long has been cut through the rocks, and a lock constructed for 

 a descent of 59 ft. in four drops. For the further regulation of the water another 

 dam has been constructed 330 miles down the river to control the irrigation below 

 that point. The most perfectly irrigated lands in Egyi)t command a rental equal to 

 about ^25 an acre, while the imperfectly irrigated land is not worth more than $5 an 

 acre. About one-third of Egypt, or some two million acres, is yet undeveloped. It 

 is estimated that the rental value will be increased nearly $30,000,000 a year by an 

 effective system of irrigation. 



Necrology. — A. Millardet, who occupied the chair of botany in the faculty of 

 .^ cience in the University of Bordeaux for 25 years, died early in December, 1902. 

 Upon his arrival at Bordeaux from the University of Nancy, the vineyards of 

 Bordeaux were suffering from the ravages of phylloxera, and he at once began the 

 investigation of that pest, studying its life history and means for preventing injury. 

 It is claimed that he was the first to point out the resistance of American grapes to 

 phylloxera and to suggest their use as stock upon which to graft the European varie- 

 ties. During this investigation he became interested in the fungus diseases of the 

 grape, particularly the downy mildew, black rot, and anthracnose, and accidentally 

 discovered the value of copper salts in preventing the development of the fungi. In 

 collaboration wdth U. Gayon he discovered the value of the fungicide now known 

 everywhere as Bordeaux mixture. To M. INIillardet is due the credit for the first 

 systematic trial of this fungicide in well-planned experiments, the results of which 

 were pul;)lished in 1885. ]\I. Millardet retired from active work in the University of 

 Bordeaux during the past year, and had been devoting himself to the reestablish ment 

 of vineyards in the calcareous soils of Saintonge, near Bordeaux. 



Antoine Ronna, the eminent engineer, died at Paris November 25, 1902. He was 

 born in London, December 9, 1830, his father being an Italian refugee, hia mother 

 the daughter of an English clergyman. He was educated in Italy and France, and 

 at different times during his life held important scientific and official positions in 



