“His method was inefficient in the extreme, for an immense ground had to be covered to get anything at all unless blind chance intervened and, at first, I was almost a sorry witness of his doings, knowing that just a little theory and calculation would have saved him 90 percent of the labor. But he had a veritable contempt for book learning and mathematical knowledge, trusting himself entirely to his inventor’s instinct and practical American sense. ”
Biographinq (2008). Thomas Edison: Life of an Electrifying Man. Filiquarian Publishing, LLC. p. 23. ISBN 978-1-59986-216-3.
See also: https://en.wikipedia.org/wiki/Nikola_Tesla#Relationships
Teaching Blog of Ioannis Souldatos 