Page 219. " but the earth's bound like iron "
Digging in permafrost
Creative Commons Attribution Share AlikeDigging in permafrost - Credit: Nick Bonzey

This is a reference to permafrost, which is soil at or below the freezing point of water.

The picture shows two men trying to dig in permafrost and having to resort to jackhammers.


Page 223. " maybe we could drop it down a fire-mine, maybe that would settle it. "


In Lyra's world a fire-mine is a geo-thermal vent.

Page 225. " I made it myself in Nova Zembla. "

Nova Zembla is an archipelago (small group or chain of islands) just east of Svalbard. In our world it is called Novaya Zemlya.

Page 225. " of narwhals clashing their long white tusks "

Page 225. " where the foul cliff-ghasts perched and swooped "

Every character in Northern Lights is at least vaguely aware of what a cliff-ghast is, and many of them – such as Serafina, Iorek and Lee – have encountered and fought them. Consequently, we as readers are never given an clear explanation.

Unlike night-ghasts (the only other kind of ghasts mentioned in the novel), cliff-ghasts appear to be mortal. They are scavengers of sorts, living off the witches and bears like vultures live off lions. They are described as being winged and having the appearance of something like a goblin.