(116) The dimensions of the coil used by the Committee of the British Association in their experiments at Kings College in 1864 were as follows Mean radius = a = .158194 metre depth of each coil = b = .01608 breadth of each coil = C = .01841 distance between the coils = .02010 number of windings n = 313 diameter of wire = .00126 The value of L derived from the first term of the expression is 437440 meters The correction depending on the radius not being infinitely great compared with the section of the coil as <s>derive<\s> found from the second term is — 7345 meters The correction depending on the diameter of the wire is per unit of length + .44997 Correction for 8 neighbouring wires + .0236 for 16 wires next to these + .0008 Correction for variation of current <s>from cent<\s> in different parts of section  .2500 Total correction per unit of length .22<s>3<\s>437 Length 311.236 meters Sum of corrections of this kind 70 meters Final value of L by calculation 430165 meters This value of L was employed in reducing the observations, according to the method explained in the Report of the Committee* <s> The results of 16 experiments in which this <\s> The correction depending on L varies as the square of the velocity. The results of 16 experiments to which this correction had been applied <s>more compared<\s> and in which the velocity varied from 100 revolutions in 17 seconds to 100 in 77 seconds were compared by the method of least squares to determine what further correction depending on the square of the velocity should be applied to make the outstanding errors a minimum * Brit Ass. Report 1863 p. 169
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Manuscript details
 Author
 James Clerk Maxwell
 Reference
 PT/72/7
 Series
 PT
 Date
 1864
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Cite as
J. C. Maxwell’s, ‘Dynamical theory of the electromagnetic field’, 1864. From The Royal Society, PT/72/7
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