Every floating thing in Aetheria, from a child’s lantern to a war-frigate, is held aloft by aetherstones. The stones are not metal and not crystal in any sense the academies have settled. They are blue at the heart, sometimes faintly green at the edges, and they remember. That is the word the old smiths use. Memory. They remember a sky from before, and being placed near them, a thing inclines toward the sky as well.
A stone the size of a thumb will lift a lantern. A stone the size of a grapefruit will lift a one-room hut, more or less. A stone the size of a melon will lift a sloop with cargo, if it is paired with another. The largest stones in the world — there are perhaps thirty of them, their locations not all public — lift the great trade-cities and the war-flagships of Ironvale.
Stones are quarried, not made. The largest seams lie in the mountainous spines of certain Upper Reach isles. The trade is old, jealously guarded, and most of its workings happen out of public view. A working stone — one already cut, tuned, and set into a ship’s heart — has its own etiquette. You do not touch another crew’s stone without asking. You do not raise your voice in the stone-room. You do not, if you are a sensible person, tell a stone what you think of it.
Smaller fragments — shards, splinters, chips — are what light ordinary homes. A good lantern-shard will glow softly for forty years. A grandmother’s shard, passed through three generations, is a serious heirloom; a young couple beginning a household will save for years to receive one as a wedding gift, or commission a new one if they cannot.
A cracked stone is bad news of a particular kind. Not always immediate disaster — many cracked stones lift their ships for years yet — but a sailor who finds a hairline in her primary stone will report it to her captain, and the captain will report it at the next port, and the harbour-master’s office will record it in a ledger that crews quietly consult before signing on.
The deepest superstition of the trade is this: a stone that sings on its own, without being struck or warmed or addressed, is trying to tell you something. Senior navigators are trained to listen. Junior crew are told not to interrupt. What the stones say, when they sing, is one of those matters the academies prefer not to discuss in writing.
“My grandmother’s lantern-shard. Forty-six years it lit her kitchen. The night she died, it was the only candle I needed. The morning after, it went grey. I keep it on the shelf above the stove. It is not glowing. But it is still mine.”
— from a letter found among the effects of a baker on Pike’s Reach