How did authors prepare figures in their publications before the advent of computers? I am often amazed at how neat figures in old scientific publications are. How did authors prepare those plots and diagrams, when there were no computers around? Did they draw them by hand? Were there any special methods and tools involved? Did the authors prepare the figures themselves?
I believe many of them did the drawing themselves with ink pen, for example. Graphs can be drawn using pins and a metal ruler: you put pins (or small nails) in a measured points of a graph, and then bend a ruler to pass through all nails. The ruler will eventually form a curve, known as a B-spline interpolant of a given set of points.