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Archimedes' screw

(Encyclopedia)Archimedes' screw, a simple mechanical device believed to have been invented by Archimedes in the 3d cent. b.c. It consists of a cylinder inside of which a continuous screw, extending the length of th...

Savery, Thomas

(Encyclopedia)Savery, Thomas, c.1650–1715, English engineer. He became a military engineer, rising to the rank of captain by 1702. He spent his free time performing experiments in mechanics, inventing such device...

cupric sulfate

(Encyclopedia)cupric sulfate ko͞oˈprĭk sŭlˈfāt, kyo͞oˈ– [key] or copper (II) sulfate, chemical compound, CuSO4, taking the form of white rhombohedral crystals or amorphous powder. It decomposes at 650℃ ...

hydroponics

(Encyclopedia)hydroponics, growing of plants without soil in water to which nutrients have been added. Hydroponics has been used for over a century as a research technique, but not until 1929 were experiments condu...

Amu Darya

(Encyclopedia)Amu Darya or Amudarya both: ämo͞oˈ däryäˈ, äˈmo͞o därˈyə [key], river, c.1,600 mi (2,580 km) long, formed by the junction of the Vakhsh and Pandj rivers, which rise in the Pamir Mts. of ce...

boiler

(Encyclopedia)boiler, device for generating steam. It consists of two principal parts: the furnace, which provides heat, usually by burning a fuel, and the boiler proper, a device in which the heat changes water in...

liposome

(Encyclopedia)liposome līˈpəsōmˌ, lĭpˈə– [key], microscopic, fluid-filled pouch whose walls are made of layers of phospholipids identical to the phospholipids that make up cell membranes. Liposomes are us...

well

(Encyclopedia)well, aperture in the earth's surface through which substances in a natural underground reservoir, such as water, gas, oil, salt, and sulfur, can flow or be pumped to the surface. In the United States...

snorkel

(Encyclopedia)snorkel, tube through which a submarine or diver can draw air while underwater. When in use, the top of the snorkel tube extends above the water surface into the air. The first snorkels were probably ...

molecular weight

(Encyclopedia)molecular weight, weight of a molecule of a substance expressed in atomic mass units (amu). The molecular weight may be calculated from the molecular formula of the substance; it is the sum of the ato...