He knew that this was an assumption admitted to be erroneous, but it afforded a good round integer to begin with, and the subsequent rectification of his calculations by the inclusion of the missing meters was but child’s-play to so transcendental a mathematician as J. T. Maston. He was so pre-occupied that he had not noticed the state of the sky—which had changed considerably during the afternoon. For the last hour one of those great storms had been gathering which affect the organizations of all living things. Livid clouds like whitish wool flocks had accumulated on the grey expanse and hung heavily over the city. The roll of distant thunder was heard. One or two flashes had already rent the atmosphere where the electric tension was at its highest. J. T. Maston, more and more absorbed, saw nothing, heard nothing. Suddenly an electric bell troubled the silence of the room with its hurried tinkling. “Good!” exclaimed the mathematician. “If interrupters can’t get in by the door, they come through the wire! A fine invention for people who wish to be left alone! I’ll see if I can’t turn that current off while I am at work!” And stepping up to the telephone, he asked,— “Who wants me?” “I want a moment’s talk with you,” said a feminine voice. “And who is speaking?” “Have you not recognized my voice, dear Mr. Maston? It is Mrs. Scorbitt.” “Mrs. Scorbitt! She will not leave me a moment’s peace.” But the last words were prudently muttered above the instrument, so that the widow heard them not. And J. T. Maston, seeing that he must say something civil, replied,— “Ah! It is you, Mrs. Scorbitt?” [Illustration: The blackboard he struck with his back. Page 57. ] “I, dear Mr. Maston!” “And what does Mrs. Scorbitt want with me?” “To tell you that there is a storm coming your way.” “Well, I cannot stop it—” “No, but I wanted to ask if you had taken care to shut your window—” Mrs. Scorbitt had hardly ended before a tremendous clap of thunder filled the air. It seemed as though a vast sheet of silk had been torn apart for an infinity of length. The lightning had flashed down over Ballistic Cottage, and, conducted by the telephone-wire, had invaded the mathematician’s room with a brutality quite electric. J. T. Maston, bending over the mouthpiece of the instrument, received the hardest voltaic knock that had ever found the mouth of a philosopher. The flash had run along his metal hook, and spun him round like a teetotum. The blackboard he struck with his back was hurled down in the corner. And the lightning disappeared out of window. Stunned for a moment—and it was a wonder it was no worse—J. T. Maston slowly rose, and rubbed the different parts of his body to make sure he was not hurt.