Page:Science vol. 5.djvu/96

 uliiding Gaiiliird, Gilibs, wid Trescn, i'9iRl)llfln!il a rii-cuit between the station of Lnngo nml iniermiHli- ate ststloni. — a circuit of which the total lenglli was SO ktlometreB (about GO miles). The wire was of uncovered chrome bronze 3.^ millimetres in dluini!' ter. The current was produced by a Siemens altera natlng machine of the Ihlrty-horse powMr type. New forms of secondary generators devised by Gaiilard and GibbB enabled the following different typing of filectrlc lighting to be maintained: 1°. At the e!qJO- siLlon building, I) liernstein lamp*, I Solell lamp, 1 Siemens lamp, Q Swan iarops, and 5 otber Bernstein lamps placed at a short distance (these lamps re- nuired dlOerent potentials]; 2°. At the station of Turin Lango, distant 10 kilometres, 34 Edison lamps of 16-CAndle power eac]i,4S of 8-civndlc power, and 1 l^iemens arc-lamp. On the 2gth of last Sep- tember the system inclnded the station of Lango, distant 40 kilomelres, whore 24 Swan lamps, re- quiring 100 voltn. were mftint*ined with perfect regu-

— At Memphis, Tenn., on the Misslstipp! River, a caving bank rises straight up from the water's edge at its base to a height of from ten to fifty feet. To check the ateady disintegration and undermining from the action of Ihe current, the U. S. engineers are employing a method of protection which has been anccessfuUy tried at other points on this river. A blanlcet or willow and pole mattress Is placed along the slope of the bank from high-water mark to the bed of the river. These mattresses are some fifty feet wide and from two hundred to a lliousand feet long, of flexible willows bound together by poles and wire. They are made on boats having n length equal to the widlli of llip mattress, and are built on an inclined platform, from which they slide down into the water as fast OS woven. They are weighted and sunk by stones, and further secured by stakes. The sunken mattresses prevent undermining below the low-water line; and the grading-down of the overhanging bank, by jets of water thrown by powerful steam-pumps, stops all undermining above that line. The space between the upper edge of the mattresses and the top of the bank is protected with willows and stone,

— In some recent investigations on the growth of leaves, published in the Journal of the tocieta i^f arl», Messrs. Zoller and Rlssmuller bave shown, that while in early cummer the leaves of plaiila contain very considerable amounts of nitrogen, phosphoric acid, and potash, these substances are withdrawn into the wood of the tree with the advancing season; so that before the leaves fade they have lost the larger )>art of what was most valuable in them, which the tree retains for Its future use. In some of these investi- gations on the leaves of the beech-tree, it was shown that In their water-free substance the highest 'per- rentage amount' of nitrogen, phosphoric acid, and potasb, is found when they open or expand in the tnonth of May, and this percentage quite regularly decreases till they ripen and tall; but the absolute itmount of nitrogen, phosphoric acid, and potash, is greatest In July, and from that time on decreases.

��— Mr, I. Millard Reade, CE-. VM.S., in his presi- dential address to the Liverpool geological society on the deinidation of the two Americas, showed thai l.M),0GO,OU0 Ions of matter in solution are annually poured into the Gulf of Mexico by the Mississippi. This, It was estimated, would reduce the time tor the denudar.lon of a foot of land over the whole hasin from a foot in six thousand years to a foot in forty-live hundred years. Similar calculations were applied to Lbe La Plata, the Amaions, and the St. Lawienee, Mr. Reade arriving at the result that an average of a hundred tons per square mile per annum are removed from the whole American continent. This agrees with results he previously arrived at for Europe: the whole drainage into the Atlantic, if reduced to twenty kilometres at two tons to the cubic yard, would equal a cubic mile .every tix

— The nectiir secretion from Aphides Is a well- known product. In many rases, however, notably the larch plant-louse, the lice so mimic the twigs on which they rest, that their presence is hard to detect, especially ns the lice are often confined to the upper branches of the trees. Often this nectar is secreted so abundantly, that the leaves, and the grass beneath the trees, are covered at early morning by drops m» large that It is ea^y to collect a considerable quantity of the nectar, SufBcient of this nectar can be secured directly from the larch lice and the elm cock's-comb gall lice to test it. Bees are also known to gather it in large quantities. This Aphis nectar is very pleat- ant and wholesome, and uDquestionably forms at times no inconsiderable portion of our most beautiful honey. Such honey is light-colored, pleasing to the taste, and perfectly safe oi a winter food for bees. Tlie truth of this statement Is sustained by the fact that the bees work freely on such nectar, even though the flowers are yielding abundant nectar at the same time. The bees lliemselves practically proclaim Ihe excellence of this Aphis nectar.

— The Royal observatory of Brussels has Issued the second part of the report upon the transit of Yenus of 1S82. Two parties were sent out by the Belgian government, one of which located at San Antonio. Tei.; the other, at Santiago, Chili. This portion of the report contains a brief narrative of the experi- ences of each party, and the detailed observations which were made. The positions of Venus on the disk were determined solely by micrometric observa- tions, which were successfully made at both stations, though clouds materially interfered with the work at San Antonio. Observations for time, latitude, longi- tude, and meteorological observations, are also given, and a chart is appended containing sketches of the optical phenomena noted at the times of contact. This report forms the second part of volume v. of the 'Annals of the observatorj'.'

— In No. 101, In the article by Mr. W. C. WInlock, entitled 'Comets and asteroids of 1884,' the date of the perihelion passage of WolPs comet should be changed from Sept, 20 to Nov. IT. The name of asteroid (237) is 'CoeleEtina,' while 'Hypatia' Is the name of (238).

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