The Three Investigators and the Secret of Terror Castle - Rough Sketch #3

This is the preliminary sketch #3 done by Harry Kane for Terror Castle. Harry's editor made some notations on the sketch for Harry to change some things when he went to do the final illustration. It reads:

HK (Harry Kane)

Text says Jupiter is holding phone next to microphone. Would you indicate that? Speaker (amplifier) is okay. Can you differentiate more between Pete and Bob? Pete is taller, huskier. Eliminate spectacles. Nobody is wearing them on jacket drawings or in other illustrations.

So if you compare the final drawing with the preliminary sketch you will see that Harry has made the changes. Adding in the microphone, changing the look of the boys and removing Pete's glasses. Of course those would get put back in for future books. A nice piece of Three Investigators history :)