"Yes. Of course I see exactly what you are driving at. Practically the whole circuit of tubes was more or less charged with a fearful admixture of gas and air. As soon as the current was switched on a spark exploded the charge. I fear, I very much fear, that you are right. If we can only find the man in charge here! But that would be nothing else than a miracle." All the same the operator in charge of the switches was close by. Fortunately for him the play of the current in the tube had carried the gases towards St. James's Street. The explosion had lifted him out of his box, and for a time he lay stunned. Dazed and confused, he had climbed to the street and staggered into the shop of a chemist who was just closing the door upon a customer who had rung him up for a prescription. But he could say very little. There had been an explosion directly he pulled down the first of the switches, and his memory was a blank after that. Anyway, the cause of the disaster was found. To prevent further catastrophe notice was immediately given to the various gas companies to cut off the supplies at once. In a little time the whole disastrous length of the tube was free from that danger. * * * * * By the afternoon a committee had gone over the whole route. At the first blush it looked as if London had been half ruined. It was impossible yet to estimate the full extent of the damage. In St. James's Street alone the loss was pretty certain to run into millions. Down in Whitehall and Parliament Street, and by Westminster Bridge, the damage was terrible. Here sharp curves and angles had checked the rush of expanding air with the most dire results. Huge holes and ruts had been made in the earth, and houses had come down bodily. Most of the people out in the streets by this time were properly equipped in indiarubber shoes and gloves. It touched the imagination strongly to know that between a man and hideous death was a thin sheet of rubber no thicker than a shilling. It was like walking over the crust of a slumbering volcano; like skating at top speed over very thin ice. Towards the evening a thrilling whisper ran round. From Deptford two early specials had started to convey an annual excursion of five hundred men and their wives to Paddington, whence they were going to Windsor. It seemed impossible, incredible, that these could have been overlooked; but by five o'clock the dreadful truth was established. Those two specials had started; but what oblivion they had found--how lingering, swift, or merciful, nobody could tell. V. There was a new horror. The story of those early special trains gave the final terror to the situation. Probably they had been blown to eternity. There was just one chance in a million that anybody had escaped. All the same, something would have to be done to put the matter at rest.