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PEOCEEDINGS OF THE AMERICAN ACADEMY 



W. G.). The curves show that with the diaphragms Nos. 21, 22, 23, 

 the maximum induced currents were 124, 93, 91, respectively, corre- 

 sponding to relative strengths of field 61, 56, 49. The results reached 

 in the earlier article are fully confirmed by these figures, which prove 

 that, within the limits of the experiments, the maximum current is 

 greater, and is reached with a stronger field, as the diaphragm is 

 thicker. 



An examination of the curves of Figure 1 shows that the point 

 of maximum current is less distinctly marked with the thinner dia- 



phragms than with the thickest. We are inclined to believe this to 

 be an accidental peculiarity, due to a slight yielding of the diaphragm, 

 which was fastened at its edges and which when thin would tend to 

 bulge towards the magnet, thus causing its whole motion to be per- 

 formed in a stronger field, and so giving rise to a stronger induced 

 current than would otherwise be the case. An extremely slight dis- 

 placement of this kind will produce a noticeable difference in the re- 

 sulting induced current. This effect may also have acted to diminish 

 somewhat the difference between the maximum current obtained with 



