The SciencesStretchers of Straw for the Dutch Army, Phonograph and other Mechanical Aids for the Aviator, and moreBy W. J. L. Kiehl on February 20, 1915AdvertisementABOUT THE AUTHOR(S)Recent Articles by W. J. L. KiehlHolland in the Grip of its Old Enemy, Preparedness in the Chemical Industries and moreFlooring the Sea with Concrete, Death of Theodore Berliner and moreZones of Silence, The Current Supplement