Boardman scale

[Richard Anderson]

Any one have a scale for a Board & Gray square? I have #6796 ca. 1862 in
the shop and the wire on the piano doesn't match the marking on the
plate. The piano has been restrung but I'm not sure if the plate is
original.

The piano is 6'8" wide with 67 plain wire bicord unisons. The markings
on the plate are as follows;

size  notes   speaking length
14     10        1 5/8"
15      8
16      7
17      7
18      7
19      9
20      7
21      6
22      4
23      2        55 7/8"

The wire on the piano seems to run about .001 (half size) less than
marked.

Would the sizes marked on the plate on a 1862 piano be equivalent to
modern wire sizes?

Thanks,
Richard Anderson, RPT
Elgin, IL