From personal experience many of the men I worked with in the foundry were at least and some times more intelligent as some of the professors I was talking courses from at UB, when it came to practical matters.
Why stop at the “practical matter”? Professor James Lawler, for example, doesn’t seem all that intelligent even at “cognitive matter.”
What do you expect? He makes his living as a philosopher. But his book was good or at least served my purposes at the time. 
