1. Ball-Point Pen   Kirkpatrick Macmillan   Roger Bacon   John J. Loud   Bardeen, Shockley, Brattain   Hint Half-n-half Clue   2. Transistor   C. F. Brush   Sir Frank Whittle   John J. Loud   Bardeen, Shockley, Brattain   Half-n-half Clue   3. Stethoscope   Dr. William Stokes, Rene Laennec   Kirkpatrick Macmillan   Andre-Marie Ampere   Roger Bacon   Half-n-half Clue   4. Electric Flat Iron   Edward Jenner   Otto   H. W. Seeley   Leo H Baekeland   Half-n-half Clue   5. Hovercraft   Dr. Alan M. Turing   Kirkpatrick Macmillan   Christopher Cockerell   Karl Benz   Half-n-half Clue   6. Barometer   Roger Bacon   William Siemens   Evangelista Torricelli   Christopher Cockerell   Half-n-half Clue   7. Electric Motor (AC)   Leo H Baekeland   John Napier   Nikola Tesla   H. W. Seeley   Half-n-half Clue