Subjects:

Engineers, War

People mentioned:

Eduard I Todleben

Subjects:

Botany, Disease, Electromagnetism, Physics, Measurement, Gas Chemistry, Geology, Engineering, Controversy

    Reports that a 'diseased coffee leaf' has been sent for examination to the Royal Botanical Gardens, Kew by the South African botanist Peter MacOwan, and Harry M Ward has found the source of the disease to be 'a typical form of the fungus Hemileia vastatrix'. At the Physical Society of London, Charles V Boys recently 'exhibited the phenomenon first observed by Faraday, that a copper disc suspended bifilarly between the poles of an electro-magnet [...] is suddenly kicked or twisted parallel with the lines of force when the magnet is excited', and Boys suggests that the phenomenon 'offers a quick and ready means of measuring the intensity of an electro-magnetic field'. Records chemical experiments made by Louis J Troost and Louis P Cailletet which, respectively, enable 'pure oxygen' to be obtained from the air and make 'the liquefaction of oxygen [...] one of the most simple operations of the laboratory'. Also describes a bitter controversy fought out in the pages of Nature between William Topley and Charles A Stevenson concerning the efficacy of an 'aseismatic joint designed [...] for mitigating the effects of shocks on lighthouses in countries subject to earthquakes' when it was tested in Japan. (644)