He developed Electrical Porcelain with transmission engineers at GE. His family continued to work at Building 68 in Schenectady for decades. William's son Frank Cermak advanced insulator design into the mid 20th century.
When Rex Harrison accepted his Academy Award for My Fair Lady (1964), he dedicated it to his two fair ladies, Audrey Hepburn and Julie Andrews both who had played Eliza Doolittle with him.
1 Both are blonde, whereas this is an error, because the original Glinda from the original 1939 film and the Glinda from the book were redheads.  In the original Wizard of Oz novel, there were two good witches and two wicked witches. Both Glinda and the Good Witch of the North are combined into one character in the 1939 film. This portrayal of Glinda stays in league to the original novel, while the real name of the Good Witch of the North varies by production.