1. Johann Gutenberg   Bicycle   Printing Press   Transistor   Carburettor   Hint Half-n-half Clue   2. Louis Pasteur   Rabies Vaccine   Logarithmic Tables   Transistor   Carburettor   Half-n-half Clue   3. John Napier   Gunpowder   Bakelite   Stethoscope   Logarithmic Tables   Half-n-half Clue   4. James Harrison, Alexander Catlin   Submarine   Gunpowder   Jet Engine   Refrigerator   Half-n-half Clue   5. Sir Isaac Pitman   Bakelite   Stethoscope   Shorthand   Ball-Point Pen   Half-n-half Clue   6. Dr. William Stokes, Rene Laennec   Submarine   Microscope   Stethoscope   Airship (rigid)   Half-n-half Clue   7. Edmund Cartwright   Shorthand   Logarithmic Tables   Power Loom   Automobiles using gasoline   Half-n-half Clue