Is it possible that the Wurlitzer tracker bar hole spacing was based
on something like the "Foot of Lahr" presumed used for the hole spacing
of the T-100 "Red" Welte-Mignon tracker bar?

A "line of Lahr" is 1/12 of an inch of Lahr, and is equal to 0.0835
standard inches.  The T-100 Welte tracker hole spacing was 1.5 lines of
Lahr, equal to 0.12526 standard inches.  This is only 2% different from
the Wurlitzer spacing of 0.1227 inches.

Edwin Welte worked in the district of Lahr in Germany, which used the
local definition of a "foot" for their measurements.  He must have used
the system he was familiar with when designing his instruments.  Could
it be that something similar is the basis for the Wurlitzer scale?

Bob Billings

 [ Wayne Stahnke wrote in 971208 MMDigest that the foot of Lahr is
 [ 12.025 modern inches in length.  Maybe Farny Wurlitzer declared,
 [ "We shall punch note holes spaced exactly 98 holes per foot, using
 [ the rule of the foot of Lahr.  That'll confound our competitors!"
 [ That spacing, expressed in modern inches, is virtually equal to the
 [ result of the precise tracker bar measurements made around 30 years
 [ ago by Wurlitzer organ expert Doyle Lane: 0.1227 inches per hole.
 [ -- Robbie