SO far, I have spoken of spectroscopes as spectroscopes -as one of the instruments the improvement of which should be cared for by every student in science. Their applications will come after. As may ...

LONDON Physical Society, June 15.—R. L. SMITH-ROSE and J. S. MCPETRIE: Measurement of the electrical constants of soil by a Lecher-wire method at a wavelength of 1-5 m. A parallel Lecher-wire system ...