THE WORLDS OF ROBERT E. SHERWOOD, Mirror to His Times by John Mason Brown. 409 pages. Harper & Row. $6.95.
The editor of Vanity Fair looked up from his desk. And up. And up. Looming above him was a young man who stood six-foot-seven and was wearing kilts. He said he wanted a job, and Editor Frank Crowninshield, delighted to have such a piece of bric-a-brac on the premises, stowed him in an office occupied by two other odd objectsDorothy Parker and Robert Benchley.
During the next 25 years, Robert Emmet Sherwood became successively a well-known movie and book reviewer, magazine editor, script...