"I have written even earlier, in 1925, some thoughts and queries of a technical character which it would be wrong to omit in these days: May there not be methods of using explosive energy incomparably more intense than anything heretofore discovered? Might not be a bomb no bigger than an orange be found to possess a secret power to destroy a whole block of buildings — nay, to concentrate the force of a thousand tons of cordite and blast a township at a stroke? Could not explosives even of the existing type be guided automatically in flying machines by wireless or other rays, without a human pilot, in ceaseless procession upon a hostile city, arsenal, camp, or dockyard? As for poison gas and chemical warfare in all its forms, only the first chapter has been written of a terrible book. Certainly every one of these new avenues to destruction is being studied on both sides of the Rhine with all the science and patience of which man is capable. And why should it be supposed that these resources will be limited to inorganic chemistry? A study of disease — of pestilences methodically prepared and deliberately launched upon man and beast — is certainly being pursued in the laboratories of more than one great country. Blight to destroy crops, anthrax to slay horses and cattle, plague to poison not armies only, but whole districts — such are the lines along which military science is remorselessly advancing. All this is nearly a quarter of a century old."