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Hardening of oak
Oat., 1877.]
,ElectroZytie JExperiments, etc.
227
Electrolytic Experiments.--M. Gramme reports three sets of experiments with his machine on the electrolysis of sulphate of copper. The results show that intensity is much more important than quantity, and that little or no work is expended in the electrolysis of sulphate of copper with copper anodes.--Gomptea Rendus. C.
Alteneck Induction-Machines.--Prof. Weinhold adds his testimony to that of the Russian experimenters, in favor of the yon Hefner-Alteneck inductors, made by Siemens and Halske, in Berlin. He represents them as having the best form for powerful currents, giving most compactly, at the least cost and with the least expenditure of power, the strongest possible currents.--Bayer. Ind.- u. (lew.Blatt. C. Geodetic Observations b y N i g h t . - - F . Perrier has made a comparative study of day and night observations, from which he concludes " that azimuthal observations by night possess a degree of precision at least equal, if not superior, to that of observations by day." He will make a special study of the effects produced upon the azimuthal measures by the torsion of the wooden ~ignals under the direct action of the sun's rays.--Comptes t~endus. C. P u l s a t i o n a n d Vibration.--C. A. Bjerknes finds that "simultaneous and synchronous vibrations manifest mean forces of the second, third and fourth degrees ; and for these new apparent forces the principle of equality between action and reaction subsists, while they also show a great resemblance to the forces of nature, Thus two spheres, having concordant pulsations~ attract each other inversely as the square of the distance ; they repel each other according to the same law if their pulsations are opposed."--Comptes Rendus. C.
Hardening of Oak.--Among the numerous instances of the hardening of oak under water, Berthier mentions remains of bridge piles, at Rouen, which were driven in 1150. They resembled ebony in texture and color, and the change was attributed to peroxide of iron. M. Charil-Marsaines, in destroying the remains of a dike which was built by Yaubam in 1681, found that the oak timbers had the same appearance. He did not examine them chemically, but he quotes experiments of Buffon, to account for the probable presence of an iron oxide.--Ann, des _Pont# et Oh. C.
,ElectroZytie JExperiments, etc.
227
Electrolytic Experiments.--M. Gramme reports three sets of experiments with his machine on the electrolysis of sulphate of copper. The results show that intensity is much more important than quantity, and that little or no work is expended in the electrolysis of sulphate of copper with copper anodes.--Gomptea Rendus. C.
Alteneck Induction-Machines.--Prof. Weinhold adds his testimony to that of the Russian experimenters, in favor of the yon Hefner-Alteneck inductors, made by Siemens and Halske, in Berlin. He represents them as having the best form for powerful currents, giving most compactly, at the least cost and with the least expenditure of power, the strongest possible currents.--Bayer. Ind.- u. (lew.Blatt. C. Geodetic Observations b y N i g h t . - - F . Perrier has made a comparative study of day and night observations, from which he concludes " that azimuthal observations by night possess a degree of precision at least equal, if not superior, to that of observations by day." He will make a special study of the effects produced upon the azimuthal measures by the torsion of the wooden ~ignals under the direct action of the sun's rays.--Comptes t~endus. C. P u l s a t i o n a n d Vibration.--C. A. Bjerknes finds that "simultaneous and synchronous vibrations manifest mean forces of the second, third and fourth degrees ; and for these new apparent forces the principle of equality between action and reaction subsists, while they also show a great resemblance to the forces of nature, Thus two spheres, having concordant pulsations~ attract each other inversely as the square of the distance ; they repel each other according to the same law if their pulsations are opposed."--Comptes Rendus. C.
Hardening of Oak.--Among the numerous instances of the hardening of oak under water, Berthier mentions remains of bridge piles, at Rouen, which were driven in 1150. They resembled ebony in texture and color, and the change was attributed to peroxide of iron. M. Charil-Marsaines, in destroying the remains of a dike which was built by Yaubam in 1681, found that the oak timbers had the same appearance. He did not examine them chemically, but he quotes experiments of Buffon, to account for the probable presence of an iron oxide.--Ann, des _Pont# et Oh. C.