(Encyclopedia) safety valve, device attached to a boiler or other vessel for automatically relieving the pressure of steam before it becomes great enough to cause bursting. The common spring-loaded…
(Encyclopedia) crabgrass, name for any of several grass species of the genera Digitaria, Eleusine, and Panicum, especially the species D. sanguinalis. Crabgrass is a common lawn weed, especially in…
(Encyclopedia) craquelurecraquelurekrăkl&oobreve;rˈ [key], hairline surface cracking of paintings into characteristic patterns determined by age, climatic conditions, and the materials used in…
(Encyclopedia) Charles, river, c.60 mi (97 km) long, rising in E Mass. and flowing generally NE to Boston Bay; it separates Boston from Cambridge. Extensive development to the riverfront includes the…
(Encyclopedia) chloral hydratechloral hydrateklōrˈəl hīˈdrāt [key], central nervous system depressant that is widely used as a hypnotic, or sleep-inducing drug. Chloral hydrate is the common…
(Encyclopedia) poltergeistpoltergeistpōlˈtərgīst [key] [Ger.,=knocking ghost], in spiritism, certain phenomena, such as rapping, movement of furniture, and breaking of crockery, for which there is no…
(Encyclopedia) strangler fig, common name for a number of tropical plant species, most of them are in the family Moraceae (fig family). They include the golden fig, Ficus aurea, of the SE United…
(Encyclopedia) tallow, solid fat extracted from the tissues and fatty deposits of animals, especially from suet (the fat of cattle and sheep). Pure tallow is white, odorless and tasteless; it…
(Encyclopedia) sorrel tree, common name for a variety of plants, including the Australian hibiscus, Hibiscus heterophyllus, of the mallow family. The staggerbush, Lyoma mariana, and the sourwood,…
(Encyclopedia) spectrophotometer, instrument for measuring and comparing the intensities of common spectral lines in the spectra of two different sources of light. See photometry; spectroscope;…
