As regards railways, it is certain that nothing is so profitable, because nothing is so cheaply transported, as passenger traffic. Goods traffic, of whatsoever description, must be more or less costly. Every article conveyed by railway requires handling and conveyance beyond the limit of the railway stations; but passengers take care of themselves, and find their own way.

Because of the way it came into existence, the solar system has only one-way traffic—like Piccadilly Circus. … If we want to make a model to scale, we must take a very tiny object, such as a pea, to represent the sun. On the same scale the nine planets will be small seeds, grains of sand and specks of dust. Even so, Piccadilly Circus is only just big enough to contain the orbit of Pluto. … The whole of Piccadilly Circus was needed to represent the space of the solar system, but a child can carry the whole substance of the model in its hand. All the rest is empty space.

It is unreasonable to expect science to produce a system of ethics—ethics are a kind of highway code for traffic among mankind—and the fact that in physics atoms which were yesterday assumed to be square are now assumed to be round is exploited with unjustified tendentiousness by all who are hungry for faith; so long as physics extends our dominion over nature, these changes ought to be a matter of complete indifference to you.

Nominally a great age of scientific inquiry, ours has become an age of superstition about the infallibility of science; of almost mystical faith in its non-mystical methods; above all—which perhaps most explains the expert's sovereignty—of external verities; of traffic-cop morality and rabbit-test truth.

Open to lawful traffic of all descriptions without toll charges.

The most important object of Civil Engineering is to improve the means of production and of traffic in states, both for external and internal trade. It is applied in the construction and management of roads, bridges, railroads, aqueducts, canals, river navigation, docks and storehouses, for the convenience of internal intercourse and exchange; and in the construction of ports, harbours, moles, breakwaters and lighthouses; and in the navigation by artificial power for the purposes of commerce. It is applied to the protection of property where natural powers are the sources of injury, as by embankments forthe defence of tracts of country from the encroachments of the sea, or the overflowing of rivers; it also directs the means of applying streams and rivers to use, either as powers to work machines, or as supplies for the use of cities and towns, or for irrigation; as well as the means of removing noxious accumulations, as by the drainage of towns and districts to ... secure the public health.

To regulate something always requires two opposing factors. You cannot regulate by a single factor. To give an example, the traffic in the streets could not be controlled by a green light or a red light alone. It needs a green light and a red light as well. The ratio between retine and promine determines whether there is any motion, any growth, or not. Two different inclinations have to be there in readiness to make the cells proliferate.

We are in the presence of a recruiting drive systematically and deliberately undertaken by American business, by American universities, and to a lesser extent, American government, often initiated by talent scouts specially sent over here to buy British brains and preempt them for service of the U.S.A. … I look forward earnestly to the day when some reform of the American system of school education enables them to produce their own scientists so that, in an amiable free trade of talent, there may be adequate interchange between our country and theirs, and not a one-way traffic.

We are like the inhabitants of an isolated valley in New Guinea who communicate with societies in neighboring valleys (quite different societies, I might add) by runner and by drum. When asked how a very advanced society will communicate, they might guess by an extremely rapid runner or by an improbably large drum. They might not guess a technology beyond their ken. And yet, all the while, a vast international cable and radio traffic passes over them, around them, and through them... We will listen for the interstellar drums, but we will miss the interstellar cables. We are likely to receive our first messages from the drummers of the neighboring galactic valleys - from civilizations only somewhat in our future. The civilizations vastly more advanced than we, will be, for a long time, remote both in distance and in accessibility. At a future time of vigorous interstellar radio traffic, the very advanced civilizations may be, for us, still insubstantial legends.

We are the generation that searched on Mars for evidence of life, but couldn’t rouse enough moral sense to stop the destruction of even the grandest manifestations of life on earth. In that sense, we are like the Romans whose works of an, architecture, and engineering inspire our awe but whose traffic in slaves and gladiatorial combat is mystifying and loathsome.
[Co-author with Anna Sequoia.]