Edison's 1000 Plus Patents.

"During his employment, Edison offered Tesla $50,000 (equivalent to about $1 million in 2006, adjusted for inflation) if he redesigned Edison's inefficient motor and generators, an improvement in both service and economy. Tesla worked night and day to redesign them and gave the Edison company several profitable new patents in the process. During the year of 1885, when Tesla inquired about the payment on the work, Edison replied to him, "Tesla, you don't understand our American humor," and reneged on his promise."