Rotary engine — The rotary engine was an early type of internal combustion aircraft engine in which the crankshaft remains stationary and the entire cylinder block revolves around it. The design was used mostly in the years shortly before and during World War I… … Wikipedia
Chainsaw safety features — Main article: Chainsaws This article is about risk control methods specific to chainsaws and chainsaw operations. Chainsaws incorporate numerous safety features common to many engine driven power tools. Manufacturers have invented numerous design … Wikipedia
building construction — Techniques and industry involved in the assembly and erection of structures. Early humans built primarily for shelter, using simple methods. Building materials came from the land, and fabrication was dictated by the limits of the materials and… … Universalium
Unusual types of gramophone records — The overwhelming majority of records manufactured have been of certain sizes (7, 10, or 12 inches), playback speeds (33⅓, 45, or 78 RPM), and appearance (round black discs). However, since the commercial adoption of the gramophone record, a… … Wikipedia
Gramophone record — A 12 inch (30 cm) 33⅓ rpm record (left), a 7 inch 45 rpm record (right), and a CD (above) A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl, the material most commonly used after … Wikipedia
nervous system, human — ▪ anatomy Introduction system that conducts stimuli from sensory receptors to the brain and spinal cord and that conducts impulses back to other parts of the body. As with other higher vertebrates, the human nervous system has two main… … Universalium
STS-121 — Infobox Space mission mission name = STS 121 insignia = STS 121 patch.png shuttle = Discovery crew members = 7 up, 6 down launch pad = LC 39B launch = July 4, 2006, 18:37:55 UTC landing = July 17, 2006, 13:14:43 UTC duration = 12 days 18 hours 37 … Wikipedia
History of the single-lens reflex camera — The history of the single lens reflex camera predates the invention of photography in 1826/27 by one and a half centuries with the use of a reflex mirror in a camera obscura first described in 1676. Such SLR devices were popular as drawing aids… … Wikipedia
List of accidents and incidents involving military aircraft, pre-1950 — This is a list of notable accidents and incidents involving military aircraft grouped by the year in which the accident or incident occurred. For more exhaustive lists, see the [http://www.baaa acro.com/ Aircraft Crash Record Office] or the [http … Wikipedia
Bicycle lighting — has two purposes: seeing and being seen. There are many types of bicycle lights available, each with its own advantages and disadvantages. There is no one best solution for any rider, and many riders mix and match different technologies to… … Wikipedia
Battery (electricity) — For other uses, see Battery (disambiguation). Various cells and batteries (top left to bottom right): two AA, one D, one handheld ham radio battery, two 9 volt (PP3), two AAA, one C, one … Wikipedia