I'll bet Charlie was VERY good at what he did.

Well, without the selenium drum Xerox would not have had nearly so nice a photocopier and without P.C. boards they would have been much more expensive.  He was their "go to" guy, especially for materials science.  And Charlie, I hope still is a great guy.  The last time I saw him was , perhaps the mid 70s and his youngest daughter was about 16, his oldest child was mid-twenties.  His son and I did audio projects together.  I haven't been in contact since the mid '90s.

"It is not necessary to have hope in order to persevere."