This is a special type of Earth model which traces its idealised "horizontal" surface - the plane on which, at any point, the pull of gravity is perpendicular to it.

BBC: Europe's Goce satellite probes Earth's gravity

The Microsoft Surface, a horizontal touch-screen computer with neither keyboard nor mouse, will go on sale in November.

ECONOMIST: Computer interfaces

Unfortunately, tragedy can strike with as simple an act as brushing one's elbow across the table, and that's all it took for me to knock my smartphone right onto a hard surface -- facedown in a perfectly horizontal position (the worst imaginable angle).

ENGADGET

The Lipsky home in Parker County, Texas sits atop an area in the vicinity of horizontal fracking lines from two gas wells about a mile below the surface.

FORBES: Promised Land's Fracking Fictions: OPEC Goes Hollywood With Crocudrama