1. Shorthand   Andre-Marie Ampere   Sir Isaac Pitman   John Napier   Alessandro Volta   Hint Half-n-half Clue   2. Jet Engine   Bardeen, Shockley, Brattain   William Siemens   Sir Frank Whittle   Lewis E. Waterman   Half-n-half Clue   3. Logarithmic Tables   Otto   Lewis E. Waterman   Andre-Marie Ampere   John Napier   Half-n-half Clue   4. Stethoscope   Dr. William Stokes, Rene Laennec   Andre-Marie Ampere   Roger Bacon   Nikola Tesla   Half-n-half Clue   5. Microscope   Z. Janssen   Dr. Alan M. Turing   John Napier   Otto   Half-n-half Clue   6. Bicycle   Evangelista Torricelli   Kirkpatrick Macmillan   Robert Wilhelm Von Bunsen   Christopher Cockerell   Half-n-half Clue   7. Submarine   David Bushnell   Roger Bacon   Robert Wilhelm Von Bunsen   Otto   Half-n-half Clue