Famous 1960s Edmund Scientific Moire Pattern Flub?

[turner3d]

Riddle me this: I counted the spokes in this Star-Trek-famous Moire Pattern No 4 on page 3 of the 1964 Edmund Scientific book "The Science of Moiré Patterns" when graphically recreating a vector version of it for my TOS communicator build, and there are 120 spokes. You can easily count them in this scan from the original book with a little patience (just count 90 degrees worth and x 4). Correct me if I'm wrong, but 360 / 120 = 3, right? If it had a spoke every 5 degrees, there would be 72 spokes, not 120. How on Earth is this famous pattern titled "Radial Lines, 5°" when there's a line every 3°? Has anyone ever noticed or pointed this out before? Am I missing something really stupid and obvious?

 

[ZeroSum]

You're right. I tested this myself in Inkscape. I drew a spoke over one on the picture then rotated it 5° - it didn't match up with the neighbouring spoke. I rotated it by 3° and it matched perfectly.