158 



The Ohio Journal of Science [Vol. XVIII, No. 5, 



the manner indicated in Blake and Sheard's paper 

 Column 20 is obtained by means of the formula 



Xs 27r 



:q. v.). 



Ko 

 K 



tan 



/2^ 



The first figure in each set in column IS is obtained by extra- 

 polation as given in Figure 7, full lines, and Figure 8, where the 

 points plotted are the remaining figures in column 18. Naturally 

 there is some degree of latitude in making this extrapolation. 

 For instance, one could so change Xi, in the sets mentioned 

 in the accompanying note, as to leave the first value in column 

 20 unchanged from the figure given in the table. We believe, 

 however, that the reader will agree from an inspection of the 

 curves of Figures 7 and 8 that the extrapolated values for Xi 

 given in the table are not greatly in error. 



Column 23 was obtained in the following way. The first 

 set of column 20 is a decreasing set, the second an increasing 

 set but in each case the first four figures are fairly constant. 

 Using the first four figures of each set and allowing for the slight 

 decrease and increase respectively the first two figures were 

 taken as given in column 23. With these two given, the remain- 

 ing figures in that column were obtained by graphical methods 

 by assuming that Ko/ k varied with y according to the relation 



1 





loge 



d+Vd^—b^ 



where d is equal to ^ and b is the radius of the plates, 



viz., 2.0 cm. Thus all the figures in column 23 except the 

 first two may be said to be extrapolated from them. Columns 

 21 and 22 are similar to columns IS and 19 respect- 



* It is to be noted that in column 5 the fundamental maximum is not exactly 

 at 150.00. For values of y less than 12 cm. this is to be explained by slight 

 inecjualities in the lengths of the wires, e. g., BM, HK, etc., leading to the plates 

 together with slight inequalities in the couplings at the four sets of plates. For 

 values of y = lo cm. say and above, at which the fundamental tends to split in two 

 the maximum is always at a length slightly greater than loO as the dotted line of 

 Curve II, Figure 5 shows. In column 19 the value of Is given for the fundamental 

 is given as if the peak were exactly at 150, i. e., l = p-150. If the value of the 

 position of the fundamental given in column 5 were used U would be slightly dif- 

 ferent from the figure given for it in column 19, being in general slightly less than 

 such figure. This would tend to raise slightly the value of the first figure in column 

 20 for sets 3 and 6 to 10 inclusive and to lower it in set 5. 



