Some of Earth-1's other super-geniuses.

[dto]

Then there was little Kathy Warren, also known as "The Kooky Genius".   :wink:  

Superboy #176 (July 1971) “The Secret of Superboy’s Sister”

http://www.geocities.com/lshonline/volume2/covers/superboy176.html

Kathy's junkyard anti-gravity raft made from a bedspring mattress with an outboard jet engine is simply CLASSIC.   :lol:


Superboy #191 (October 1972) “The Kid With the Super-Brain”

http://www.geocities.com/lshonline/volume2/covers/superboy191.html

[llozymandias]

There is also: Carl Draper/the Master Jailer.  Dr. Albert Michaels/the Atomic Skull.  Winslow P. Schott/the Toyman.

[NotSuper]

The Prankster and Emmet Vale would also qualify.