Gluttony is the source of all our infirmities, and the fountain of all our diseases. As a lamp is choked by a superabundance of oil, a fire extinguished by excess of fuel, so is the natural health of the body destroyed by intemperate diet.

Is fuel efficiency really what we need most desperately? I say that what we really need is a car that can be shot when it breaks down.

The animal frame, though destined to fulfill so many other ends, is as a machine more perfect than the best contrived steam-engine—that is, is capable of more work with the same expenditure of fuel.

Until that afternoon, my thoughts on planetary atmospheres had been wholly concerned with atmospheric analysis as a method of life detection and nothing more. Now that I knew the composition of the Martian atmosphere was so different from that of our own, my mind filled with wonderings about the nature of the Earth. If the air is burning, what sustains it at a constant composition? I also wondered about the supply of fuel and the removal of the products of combustion. It came to me suddenly, just like a flash of enlightenment, that to persist and keep stable, something must be regulating the atmosphere and so keeping it at its constant composition. Moreover, if most of the gases came from living organisms, then life at the surface must be doing the regulation.

We used to be a source of fuel; we are increasingly becoming a sink. These supplies of foreign liquid fuel are no doubt vital to our industry, but our ever-increasing dependence upon them ought to arouse serious and timely reflection. The scientific utilisation, by liquefaction, pulverisation and other processes, or our vast and magnificent deposits of coal, constitutes a national object of prime importance.