Of course it had always been there, she said to herself,--only people were too dull and unenterprising to discover it,--besides, if they had ever found it (certain travellers having declared they had seen it in the distance) they would not have been allowed to approach it.

This fact was the one point that chiefly dwelt in her mind--a secret of science which she puzzled her brain to fathom.
What could be the unseen force that guarded the city ?--girding it round with an unbreakable band from all exterior attack?
A million bombs could not penetrate it,--so had said the Voice travelling to her ears on the mysterious Sound Ray.

She thought of Shakespeare's lines on England-- "This precious stone set in the silver sea Which serves it in the office of a wall, Or as a moat defensive to a house Against the envy of less happy lands." Modern science had made the sea useless as a "wall" or "moat defensive" against attacks from the air,--but if there existed an atmospheric or "etheric" force which could be utilised and brought to such pressure as to encircle a city or a country with a protective ring that should resist all effort to break it, how great a security would be assured "against the envy of less happy lands"! Here was a problem for study,--study of the intricate character which she loved--and she became absorbed in what she called "thinking for results," a form of introspection which she knew, from experience, sometimes let in unexpected light on the creative cells of the brain and impelled them to the evolving of hitherto untried suggestions.

She sat quietly with a book before her, not reading, but bent on seeking ways and means for the safety and protection of nations,--as bent as Roger Seaton was on a force for their destruction.

So the hours passed swiftly, and no interruption or untoward obstacle hindered the progress of the "White Eagle" as it careered through the halcyon blue of the calmest, loveliest sky that ever made perfect weather, till late afternoon when it began to glide almost insensibly downward towards earth.