Helicopter, 1930. Inventor: d’ Ascanio (Italy). Co-axial machine. Earliest drawing of principle, Le Mans Museum, France, c. 1460. First service able machine by Igor Sikorsky (USA).1939.
![](https://syskool.com/wp-content/uploads/2013/12/CH-146_Griffon_Helicopter-1.jpg)
Helium, 1868. Inventor: Sir William Ramsay (Great Britain).
![](https://syskool.com/wp-content/uploads/2013/12/Helium-glow-1.jpg)
Hovercraft, 1955. Inventor: C.S. Cockerell (England). Patented December 12. Earliest air-cushion vehicle patent was in 1877 by J.I. Thornycroft (1843-1921) (England). First ‘light’ Saunders Roe SRNI at Cowes, England, (May 30, 1959).
![](https://syskool.com/wp-content/uploads/2013/12/Hovercraft_retusche_Ausschnitt-1.jpg)
Internet, March 20, 1989 Inventor: Tim Burners-Lee
Iron Working, c. 1000 BC. Inventor: Hallstatt, Austria. Introduced into Britain c. 550 BC.
![](https://syskool.com/wp-content/uploads/2013/12/internet-pic-1.jpg)
Jet Engine, 1937. Inventor: Sir Frank Whitde (England) (b. 1906). First test-run in 1937. Principles announced by Merconnet (France) 1909 and Maxime Guillaume (France) 1921. First flight August 27, 1939 by Heinkel He.
![](https://syskool.com/wp-content/uploads/2013/12/Pratt_amp_Whitney_J58-1.jpg)
Laser, 1960. Inventor: Dr. Charles H. Townes (USA). First demonstration by Theodore Maiman (USA). (Abbreviation for Light Amplification by Stimulated Emission of Radiation).
![](https://syskool.com/wp-content/uploads/2013/12/RGB_laser-5-1.jpg)
Lathe, c. 1500 BC. Inventor: Greeks for wood-working. Possibly developed from potter’s wheel. Earliest screw cutting lathe by Henry Maudsly (England) (1771-1831).
![](https://syskool.com/wp-content/uploads/2013/12/lathe_05-1.jpg)
Launderette, 1934. Inventor: J.F. Cantrell (USA), Fort Worth, Texas, April 18.
![](https://syskool.com/wp-content/uploads/2013/12/launderette-1.jpg)
Laws of Gravitation and Motion,
1687. Inventor: Isaac Newton
(England).
![](https://syskool.com/wp-content/uploads/2013/12/download-7.jpg)
Lightning Conductor, 1752. Inventor: Benjamin Franklin (USA) (1706-90), Philadelphia.
![](https://syskool.com/wp-content/uploads/2013/12/Lightning_Strike-1.jpg)
Linoleum, 1860. Inventor: Frederick Walton (England).
![](https://syskool.com/wp-content/uploads/2013/12/download-1-3.jpg)
Locomotive, 1804. Inventor: Richard Trevithick (England) (1771- 1833). Penydarren, Wales, 9 Miles (February 21).
![](https://syskool.com/wp-content/uploads/2013/12/Locomotive_Great_Northern_Railway_US-1.jpg)
Loom (power), 1785. Inventor: Edmund Cartwright (England) (1743- 1823).
![](https://syskool.com/wp-content/uploads/2013/12/download-2-3.jpg)
Loudspeaker, 1924. Inventor: Rice- Kellogg (USA).
![](https://syskool.com/wp-content/uploads/2013/12/download-3-2.jpg)