. The London, Edinburgh and Dublin philosophical magazine and journal of science. lace-ment which would be produced by an alteration of the differ-ence of phase by one tenth of a period—would have beenvisible to the eye. In our next experiment the spark-gap at c was removed,and the wires of the secondary circuit were led to earth afterpassing round the three sides ab, be, cd of the square—parallelto the beams and so as to include the beams between same damping was kept in this circuit. The wires wereinsulated on paraffin blocks and strips of tinfoil hung overthem to a depth of 3 centi
. The London, Edinburgh and Dublin philosophical magazine and journal of science. lace-ment which would be produced by an alteration of the differ-ence of phase by one tenth of a period—would have beenvisible to the eye. In our next experiment the spark-gap at c was removed,and the wires of the secondary circuit were led to earth afterpassing round the three sides ab, be, cd of the square—parallelto the beams and so as to include the beams between same damping was kept in this circuit. The wires wereinsulated on paraffin blocks and strips of tinfoil hung overthem to a depth of 3 centim. throughout their length, thusgiving sides to the electric waves (fig. 2). When the secondary plates discharge, a positive currentruns down the one wire and a negative current down the 24 Messrs. Henderson and Henry on the Motion other. We may therefore consider the space between thestrips to be filled with tubes of forces stretching horizontallyacross perpendicular to the beams of light and moving alongin the direction of the transmitted beam. If these tubes of Fiff. R,R= damping resistances. force drag the tether with them, a displacement as alreadydescribed should be observed in the interference-bands, when,after being short-circuited, these parallel wires are suddenlyintroduced into the circuit. In our experiments, however, we again failed to detect anymotion. At this point we may find what minimum velocityof the aether would have been detected by this method. Let u = velocity of the aether,v = „ „ light,d = path of light in moving aether,\ = wave-length of light v + u = velocity of one beam, v — u = velocity of other beam ; —— = time taken by first beam to travel distance d, d v—u 2nd~2 o= difference of time occupied by the two beams in passing round the square. and second Denote this time by r. For of the JEther in an Electromagnetic Field. 25 Let T = nT, where T is the period of vibration of the light used. There will therefore be a displa
Size: 1451px × 1722px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, bookidlondon, booksubjectscience
