Lots of my profs were this way. They made much more from their patent and other royalties in the Mining and Oil and Gas fields than they did from their teaching

Lots of my profs were this way. They made much more from their patent and other royalties in the Mining and Oil and Gas fields than they did from their teaching gigs. One told me once that the money he made from teaching didn't even pay his income tax. I went to a school that is one of the top for those industries, for context.