A question for those well versed in the realm of string scales

[RustRazor@AOL.COM]

Hello all,

I'm rebuilding a 4'9" Henry F Miller Grand (c 1920).  The odd thing is:  
After carefully measuring the string diameters, it seems that they don't 
change in a linear fashion.  In fact, there is a range where the gage goes 
from 18 to 17 to 17.5 to 16.

My question is:  Is this abnormal?  I haven't done that much restringing but 
I always thought the diameters were supposed to keep decreasing (or 
increasing from the other way).

Matt.