1. James Harrison, Alexander Catlin   Printing Press   Electronic Computer   Refrigerator   Carburettor   Hint Half-n-half Clue   2. Otto   Airship (rigid)   Refrigerator   Automobiles using gasoline   Internal Combustion Engine   Half-n-half Clue   3. Roger Bacon   Refrigerator   Gunpowder   Ball-Point Pen   Microscope   Half-n-half Clue   4. Dr. William Stokes, Rene Laennec   Stethoscope   Ball-Point Pen   Transistor   Microscope   Half-n-half Clue   5. John Napier   Barometer   Automobiles using gasoline   Logarithmic Tables   Stethoscope   Half-n-half Clue   6. Sir Frank Whittle   Power Loom   Submarine   Jet Engine   Fountain Pen   Half-n-half Clue   7. Karl Benz   Fountain Pen   Automobiles using gasoline   Jet Engine   Transistor   Half-n-half Clue