Heavyside Layer

There is a million dollars’ worth of equipment up above us in the rock galleries, Mister Bond, sending fingers up into the Heavyside Layer, waiting for the signals, jamming them, countering beams with other beams.

DR. NO, Chapter 16

Doctor No is continuing to brag to James Bond about his installation on Crab Key, having just named a bunch of armed missiles that he has interfered with on behalf of the Russians.

Fleming tosses in a reference to the Heavyside Layer, referring to the Heaviside layer, sometimes called the Kennelly–Heaviside layer. This is a region of the Earth’s ionosphere, between roughly 90 and 150 km above the ground.

This region was predicted separately and at almost the same time by Arthur E. Kennelly and Oliver Heaviside. At the time the use of radio waves was in its infancy, and scientists didn’t understand why radio waves followed the curve of the earth rather than shooting directly out into space.

Heaviside, a self-taught British engineer, hypothesized in 1902 that there was a layer in the Earth’s atmosphere that forced radio waves to skim around the planet.

This led to great advances in radio technology so that by the time of Doctor No, it was possible not only to guide missiles by radio but also to intercept them.

Doctor No states that “And we track it, as accurately as they are tracking it in the Operations Room on Turks Island.”

The ninth was the top floor of the building. Most of it was occupied by Communications, the hand-picked inter-services team of operators whose only interest was the world of microwaves, sunspots, and the ‘heaviside layer’. Above them, on the flat roof, were the three squat masts of one of the most powerful transmitters in England, explained on the bold bronze list of occupants in the entrance hall of the building by the words ‘Radio Tests Ltd.’

Moonraker, Chapter 2

The term (with the correct spelling) also appears in Moonraker in a description of MI6 headquarters building.