This stirring scene is the cover for the sheet music for a song published in 1913, Britannia Must Rule the Air, written by Frank Duprée and composed by Charles Ashley. It shows a reasonable (if stubby) approximation of a Zeppelin in the process of being destroyed by gunfire from two aeroplanes, a Farman-type biplane and a monoplane.
The lyrics are a little more subtle:
When wooden walls and straining sails bore Britain's flag afar,
The Nation prospered well in peace and feared no foe in war,
For Britain's might was ev'rywhere and ruled the endless waves,
Proclaiming to the world at large 'we never shall be slaves.'
And when the ironclad replaced the ships that caught the breeze
Britannia still retained her throne up on the charted seas,
For frowning fleets and giant guns outnumbered two to one
The navies of all other lands beneath the sov'reign sun.
And now that ev'ry cloud conceals a lurking bird of prey,
Which threatens our supremacy in peace and war today,
Britainnia must be equal to the peril and prepare
To hold our Empire sacred from these dreadnaughts of the air.
Britannia must rule the air
As still she rules the sea,
To guard this realm beyond compare
And keep her people free.
Britannia, Britannia must like the eagle be;
Britannia, Britannia must rule both air and sea!
Britannia, Britannia must rule both air and sea.
The message is clear enough: just as Britain's naval superiority has kept it safe from the Napoleonic Wars through the ironclad era to now, so must it have a superiory aerial superiority to safeguard its freedom in the new century. This was exactly the comparison and the message of the Navy League in response to German aerial superiority, as supposedly revealed by the phantom airships supposedly seen flying all over Britain.