First Lensman by E.E. Smith

Forty thousand miles from Earth's center the _Chicago_ loafed along a circular arc, inert, at a mere ten thousand miles an hour; a speed which, and not by accident, kept her practically stationary above a certain point on the planet's surface. Nor was it by chance that both Virgil Samms and Roderick Kinnison were aboard. And a dozen or so other craft, cruisers and such, whose officers were out to put space-time in their logs, were flitting aimlessly about; but never very far away from the flagship. And farther out -- well out -- a cordon of diesel-powered detector ships swept space to the full limit of their prodigious reach. The navigating officers of those vessels knew to a nicety the place and course of every ship lawfully in the ether, and the appearance of even one unscheduled trace would set in motion a long succession of carefully-planned events.

And far below, grazing atmosphere, never very far from the direct line between the _Chicago_ and Earth's core, floated a palatial pleasure yacht. And this craft carried not one Lensman, or two, but eight; two of whom kept their eyes fixed upon their observation plates. They were watching a lunch-box resting upon the bottom of a lake.