The origin of a straight line/flat surface

[rowrrbazzle]

My post from an earlier thread:

@rowrrbazzle

FYI the earliest known devices to draw theoretically straight lines are the Sarrus linkage and the Peaucellier-Lipkin linkage.

Sarrus linkage - Wikipedia

Peaucellier–Lipkin linkage - Wikipedia

The arms of the Peaucellier-Lipkin linkage don’t have to be straight. Only the indicated distances must be equal. This can be accomplished by stacking those arms and drilling through them all at once.

I’m not sure if an analogous construction method can be used with the Sarrus linkage, but it seems simple enough that the ancients could have discovered it.