How is a zig-zag numbering any less valid than any other method? Your mapping a two dimensional space with what is essentially a line. Sometimes it doesn’t make sense for there to be discontinuities in the numbering, as one would have to do if the numbers always incremented in the same direction. Would you prefer that the numbers follow the path of a Hilbert Curve?
To answer your question though, surveyors have been using this method to number sections of land for much longer than you or I have been alive.
How is a zig-zag numbering any less valid than any other method? Your mapping a two dimensional space with what is essentially a line. Sometimes it doesn’t make sense for there to be discontinuities in the numbering, as one would have to do if the numbers always incremented in the same direction. Would you prefer that the numbers follow the path of a Hilbert Curve?
To answer your question though, surveyors have been using this method to number sections of land for much longer than you or I have been alive.