“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.

I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor." - Nikola Tesla

I'm sure Edison was crying all the way to the bank over the labour he expended.

Oh, Nikola -- missed your chance for an extra jibe in there. "...a little theory and calculation" -- and a big electromagnet, assuming a ferric needle.