Moons Simile
The stars that Caspian is looking at are described as looking like two small moons which emphasizes their brightness and clarity. Since the moon is closer to earth, it is brighter (this applies in Narnia too, apparently) and that is why the extra-bright stars are compared to it.
By The Lion's Mane Metaphor
The phrase "By The Lion's Mane" is a metaphor for something that is being sworn by. It metaphor for something that can be trusted, and for an oath that is sworn to show sincerity. It is also a metaphor for a member of the Old Narnian races who swear by the power and the way of Aslan.
Wet Blanket Metaphor
A wet blanket is a British metaphor for someone who is putting a dampner on things and putting out the joy and spark in things. A web blanket is placed ove a fire to put it out and this moniker directed at someone is a metaphor for the effect that they have on joy and liveliness.
Wild Goose Chase Metaphor
A wild goose chase is a metaphor for an endeavor that is a complete waste of time and guaranteed to be fruitless. Chasing wild geese is guaranteed to be unsuccessful as they are impossible catch, and impossible to find in the first place. The metaphor is used to refer to exercises in futility that will never achieve their original goal.
Black Mist Simile
As the woods were moving to join Aslan and the revellers at the Bacchanal they looked to Lucy and Susan like a black mist rising. This comparison is made because there are so many trees on the move that they are indistinguishable from each other and look like a rising mist. The fact they seem to be rising and moving as one also makes this comparison even more accurate. MIsts tend to rise in a line and this line of trees that are dancing individually are actually so in-sync with each other that they appeared like a black mist to the two girls.
