Transcriber’s Note

Two words on the first line of p. [70] of this edition (noted below) were missing (blank). They have been supplied from the 5th edition, published in 1920.

On p. 226, a footnote at ([226.42]) refers to Mr. H. G. Wells’s tale, The New Accumulator, which is certainly a reference to his 1901 tale “The New Accelerator”.