1. Dr. Wallace H. Carothers   Barometer   Stethoscope   Transistor   Nylon   Hint Half-n-half Clue   2. William Siemens   Electric Furnace   Electric Motor (AC)   Logarithmic Tables   Fountain Pen   Half-n-half Clue   3. Edward Jenner   Air Pump   Vaccination   Shorthand   Logarithmic Tables   Half-n-half Clue   4. C. F. Brush   Gunpowder   Jet Engine   Arc Lamp   Electric Furnace   Half-n-half Clue   5. Nikola Tesla   Printing Press   Arc Lamp   Airship (rigid)   Electric Motor (AC)   Half-n-half Clue   6. Sir Isaac Pitman   Shorthand   Logarithmic Tables   Transistor   Microscope   Half-n-half Clue   7. David Bushnell   Submarine   Hovercraft   Gunpowder   Shorthand   Half-n-half Clue