Dear Mr. Darryl Rehr
In QWERTY Revisited（ on ETCetra No.38 / March, 1997/3 ）, there are ,
If you've ever had the opportunity to fiddle with a Sholes & Glidden, you may have a feel for how this works. Type keys for two adjacent type bars quickly in succession and they'll clash and jam all day.
Who wrote this article, do you know?
Associate Professor Koichi Yasuoka says they never jam.
Koichi Yasuoka, The Truth of QWERTYhttp://yasuoka.blogspot.com/2009/05/with-older-manual-typewriters-each.html
"They are called upstrike typewriters and their typebars never jam."
How do you think?