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Basic diagram of an onager, a type of catapult. A catapult is a ballistic device used to launch a projectile a great distance without the aid of gunpowder or other propellants – particularly various types of ancient and medieval siege engines. [1] A catapult uses the sudden release of stored potential energy to propel its payload.
A slingshot or catapult is a small hand-powered projectile weapon. The classic form consists of a Y-shaped frame, with two tubes or strips made from either a natural rubber or synthetic elastic material. These are attached to the upper two ends. The other ends of the strips lead back to a pouch that holds the projectile. One hand holds the ...
The mechanical production of dry photographic plates were invented by George Eastman who filed U.S. patent #226,503 on September 9, 1879, for (in his own words "An Improved Process for Preparing Gelatine Dry-Film Plates") which was issued to him on April 13, 1880. [156] [231] 1879 Carton
Simeon North (July 13, 1765 – August 25, 1852) was an American gun manufacturer, who developed one of America's first milling machines (possibly the very first) in 1818 and played an important role in the development of interchangeable parts manufacturing.
2004: First podcast, invented by Adam Curry and Dave Winer, is a program made available in digital format for download over the Internet and it usually features one or more recurring hosts engaged in a discussion about a particular topic or current event. [544] [545] [546] 2005: YouTube, the first popular video-streaming site, was founded
Tapered roller bearings are bearings that can take large axial forces as well as being able to sustain large radial forces. They were co-invented by German-American Henry Timken and Reginald Heinzelman. [56] On August 27, 1897, Timken and Heizelman filed U.S. patent #606,635 which was issued to them jointly on June 28, 1898. [57] 1897 Ice cream ...
The National Catapult Contest originated out of a simple directive from the Academic Development Committee of Indianapolis' Park School for Boys (now Park Tudor School) in December 1965, which "urged the faculty to review continuously the content and method of their instruction," and "further, not to forego unusual methods of stimulating the interest and involvement of students."
Rhodes, Edward, ed. Engineering America: The Rise of the American Professional Class, 1838–1920 (Washington: Westphalia Press, 2014) 142 pp. Smith, Edgar C. A short history of naval and marine engineering (Cambridge University Press, 2013) Usher, Abbott Payson. A History of Mechanical Invention (2nd ed. 1954), 450 pp. online review