Values across a surface

One value at every point of a plane that is not a map: a slice of air, a sheet of metal, a pair of measurements. The forms here show how it rises and falls across the plane.

Studied from its original page 3

• 

  Isobaric-isosteric unit-tubes (solenoid count)

  V. Bjerknes and J. W. Sandstrom · 1910

  Two families of lines over a slice of the atmosphere, spaced so that every small cell where they cross stands for the same amount.

• Slotted interlocking-card surface model

  E. S. Farwell (data), via the American Machinist; described by Willard C. Brinton · by 1914

• 

  Transformation grids

  D'Arcy W. Thompson · 1917