1. Roger Bacon   Stethoscope   Rabies Vaccine   Fountain Pen   Gunpowder   Hint Half-n-half Clue   2. Dr. William Stokes, Rene Laennec   Laboratory Gas Burner   Barometer   Ball-Point Pen   Stethoscope   Half-n-half Clue   3. Gottlieb Daimler   Carburettor   Gunpowder   Airship (rigid)   Printing Press   Half-n-half Clue   4. Sir Frank Whittle   Laboratory Gas Burner   Jet Engine   Internal Combustion Engine   Automobiles using gasoline   Half-n-half Clue   5. Lewis E. Waterman   Fountain Pen   Microscope   Power Loom   Gunpowder   Half-n-half Clue   6. Robert Wilhelm Von Bunsen   Laboratory Gas Burner   Rabies Vaccine   Microscope   Ball-Point Pen   Half-n-half Clue   7. Dr. Alan M. Turing   Automobiles using gasoline   Fountain Pen   Laboratory Gas Burner   Electronic Computer   Half-n-half Clue