Page:A hundred years hence - the expectations of an optimist (IA hundredyearshenc00russrich).pdf/123

 leaks into a manhole or inspection chamber, forming an explosive mixture of gas and air, which presently becomes ignited by an electric spark and blows up the whole affair. No doubt coal gas is within easily measurable distance of its end as a convenience of civilisation, But it is extremely probable that hydrogen and oxygen will be conveyed by mains to houses and public buildings during a long time: and it is hardly possible to believe that the mains will not sometimes leak and be capable of letting out mixtures far more dangerous on ignition than the mixture of coal gas and air, and still more dangerous because neither of the gases, nor the mixture of them, has any smell, unless indeed we should take the precaution of giving them one artificially. Whatever we may do, and we shall do much, to minimise the dangers of highly-evolved civilisation, accidents will always occur, and their violence will probably increase. We must pay our toll to the conveniences of life, and we shall of course compensate ourselves by a lower death-rate from diseases, many of which will no doubt in a hundred years' time have disappeared from the planet.

If we need any motive power other than electricity, or if we need motive power of some other kind to produce electricity, no doubt the explosive recombination of oxygen and hydrogen, controlled by devices developed from existing gas-engines and petrol-engines, will be