On Wed, 23 Dec 2009 10:06:38 +0000 I wrote: > Vernon Bedford published a method like this, which he called simply > Differential Maximus, in (I think) the early 70's. RW 1971 p418. -36-16.3478.56.34.7t.34.56.34.16-36.147t-145t-3t-1t-10 -1t-169t.70-7t.90.78.90.16.90.78.5690.7t-70-189t division head 1t SH