For thousands of years the big brain served as a master switchboard for the thoughts and emotions of humanity. Now the central mind was showing signs of decay ... and men went mad. Illustrated by BIRMINGHAM The trouble began in a seemingly trivial way. Connor had wanted to speak to Rhoda, his wife, wished himself onto a trunk line and then waited. "Dallas Shipping here, Mars and points Jupiterward, at your service," said a business-is-business, unwifely voice in his mind. "I was not calling you,