Page 326. " There were iron brackets every few yards, holding blubber lamps "
Whale Blubber
Creative Commons Attribution Share AlikeWhale Blubber - Credit: Susanna Haas

Whale blubber was melted down and used as oil in lamps as far back as the 1700s, but it was very expensive. In the 19th century, cheaper oils such as kerosene (or naptha, as it is known in Lyra's world) replaced whale blubber as lamp oil.


Page 328. " I am the Regius Professor of Cosmology at the University of Gloucester. "

The Regius Professorships are "royal" professorships at the ancient universities of Britain.

However Gloucester, in our world, is not one of the ancient universities.  The University of Gloucestershire was established in 2001.

Page 329. " He's nothing but a popinjay! "
Green woodpecker
Creative Commons Attribution Share AlikeGreen woodpecker - Credit: Sven Teschke

A popinjay is a British woodpecker, specifically the green woodpecker.

However the word is also used to describe someone vain, self-important or vapid, as here.

Page 330. " There is a correspondence between the microcosm and the macrocosm! "

Microcosm and macrocosm is the idea that the same patterns are reproduced at all levels of nature, from the largest scale (the macrocosm) to the smallest (the microcosm).

Page 332. " They wouldn't fight him honourably like a bear; they'd kill him with fire-hurlers before he got near. "

Fire hurlers seem to be a cross between a cannon and a flame thrower that is regularly used as a weapon by the bears, and they make a reappearence later in the trilogy.

Page 341. " for bears were brought up by their mothers "
A polar bear with her cubs
Creative Commons AttributionA polar bear with her cubs - Credit: Dmitry Rozhkov

Polar bears in our own world are also nursed by their mothers until they reach about two and a half years.

Female polar bears are noted for their affection towards, and fierce defence of, their cubs.

Page 350. " Then with a roar and a blur of snow both bears moved at the same moment. "


The fight between the two bear kings is vicious and violent in Northern Lights, as is a fight between real polar bears.