Show THE navigation in fogs is attended by terrible d digera as altered by the recent dreadful collisions of alie nar anil stonington in the sound and the queen and anchoria in open sea it becomes thereby a very prominent query whether the means now employed for discovering ho position and nearness of vessels are at all commensurate with the necessities of the case electric headlights project a beam of electric light through the densest fog for ft thousand feet or more and through ordinary fogs a distance several times as great except in very rough weather the steam can be beard at a long distance but it is liable to be a treacherous asit is not always poa to determine by the ear alone the direction from which a sound comes this great defect is remedied by a recent invention of the celebrated prof A M mayor the topo of which alie scientific american given an illustration and description the direction con lifts of two attached to a connecting bar or shoulder rest the sound receivers are joinell by flexible bubea which amlo for part of choir ad frodi which ear tube proceed one tube carries a telescopic teles copia device by its length can be varied when the tap twp face alie darf action clience a sound camp eo a to receive simul luneo t ho garni BO in pulse and anro joined by tubes of equal length the found received from bliem nee ily patch ather and the bound frill be r on ahr contrary alia reo natora being in tl earne pochion as regard the tourch of sound the resonator tubes differ in lecig h by half the wave length ol 01 the the me neutralize iha from the other and the bound ia obliterated with buah a help the pilot in afo need losyer be long in daubl a to the direction f yr nini sigual aal if not d be he ran luish df lay by buado and a little calculation innately at leant the af pf ih sounding boily thus science advances alwa s more nud more in relieving and di aster |