A weather house is a folk art device in the shape of a small German or Alpine chalet that indicates the weather. A typical weather house has two doors side by side. The left side has a girl or woman, the right side a boy or man. The female figure comes out of the house when the weather is sunny and dry, while the male (often carrying an umbrella) comes out to indicate rain.
In fact, a weather house functions as a hygrometer embellished by folk art. The male and female figures ride on a balance bar, which is suspended by a piece of catgut or hair. The gut relaxes or shrinks based on the humidity in the surrounding air, relaxing when the air is wet and tensing when the air is dry. This action swings one figure or the other out of the house depending on the humidity. [1] Some variants function as a barometer: low pressure indicates bad (rainy) weather, high pressure good (sunny) weather.
The first written mention is in 1726, Theatrum Aerostaticum by Jacob Leupold, who describes a (hygrometer type) weather house he constructed many years before. An encyclopedia entry by 1735 (Zedlersches Lexikon) mentions weather houses as commonly available on markets.
Weather houses are associated in the popular mind with Austria, Germany or Switzerland, and are often decorated in the style of a cuckoo clock. They are often sold as "typical German" souvenirs to travellers from other countries. Many weather houses also bear a small thermometer on the part between the two doors that conceals the gut suspension, and many also contain a piggy bank.
In contrast, the term "weather house" in the United States referred to buildings built by the U. S. Signal Service and then the U. S. Weather Bureau to house the instruments and Chief Weather Observers so that they could do their job. The National Weather Service, the successor to the U. S. Weather Bureau, now uses the term "shelter."
A one-act English comic opera called Weather or No , about the male and female figures in a weather house falling in love, became popular when it was played as a companion piece to The Mikado in 1896-97.
The Brollys is an animated television series about a boy who is magically transported every night into the weather house on the wall of his bedroom.
Weather houses are mentioned in the novel Wintersmith by Terry Pratchett.
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
The dew point of a given body of air is the temperature to which it must be cooled to become saturated with water vapor. This temperature depends on the pressure and water content of the air. When the air is cooled below the dew point, its moisture capacity is reduced and airborne water vapor will condense to form liquid water known as dew. When this occurs through the air's contact with a colder surface, dew will form on that surface.
The horse latitudes are the latitudes about 30 degrees north and south of the Equator. They are characterized by sunny skies, calm winds, and very little precipitation. They are also known as subtropical ridges or highs. It is a high-pressure area at the divergence of trade winds and the westerlies.
A hygrometer is an instrument which measures the humidity of air or some other gas: that is, how much water vapor it contains. Humidity measurement instruments usually rely on measurements of some other quantities such as temperature, pressure, mass and mechanical or electrical changes in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity. Modern electronic devices use the temperature of condensation, or they sense changes in electrical capacitance or resistance to measure humidity differences. A crude hygrometer was invented by Leonardo da Vinci in 1480. Major leaps came forward during the 1600s; Francesco Folli invented a more practical version of the device, while Robert Hooke improved a number of meteorological devices including the hygrometer. A more modern version was created by Swiss polymath Johann Heinrich Lambert in 1755. Later, in the year 1783, Swiss physicist and Geologist Horace Bénédict de Saussure invented the first hygrometer using human hair to measure humidity.
Weather lore is the body of informal folklore related to the prediction of the weather and its greater meaning.
An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning systems, which use vapor-compression or absorption refrigeration cycles. Evaporative cooling exploits the fact that water will absorb a relatively large amount of heat in order to evaporate. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation). This can cool air using much less energy than refrigeration. In extremely dry climates, evaporative cooling of air has the added benefit of conditioning the air with more moisture for the comfort of building occupants.
June Gloom is a California term for a weather pattern that results in cloudy, overcast skies with cool temperatures during the late spring and early summer. While it is most common in the month of June, it can occur in surrounding months, giving rise to other colloquialisms, such as “Graypril,” "May Gray," "No-Sky July," and "Fogust." Low-altitude stratus clouds form over the cool water of the California Current, and spread overnight into the coastal regions of California.
Psychrometrics is the field of engineering concerned with the physical and thermodynamic properties of gas-vapor mixtures.
The wet-bulb globe temperature (WBGT) is a type of apparent temperature used to estimate the effect of temperature, humidity, wind speed, and visible and infrared radiation on humans. It is used by industrial hygienists, athletes, sporting events and the military to determine appropriate exposure levels to high temperatures. It is derived from the following formula:
A humidifier is a household appliance or device designed to increase the moisture level in the air within a room or an enclosed space. It achieves this by emitting water vapor or steam into the surrounding air, thereby raising the humidity levels.
This article presents common techniques and facts regarding the cultivation of cannabis, primarily for the production and consumption of its infructescences. Cultivation techniques for other purposes differ.
A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For instance, cold fronts can bring bands of thunderstorms and cumulonimbus precipitation or be preceded by squall lines, while warm fronts are usually preceded by stratiform precipitation and fog. In summer, subtler humidity gradients known as dry lines can trigger severe weather. Some fronts produce no precipitation and little cloudiness, although there is invariably a wind shift.
The wet-bulb temperature (WBT) is the temperature read by a thermometer covered in water-soaked cloth over which air is passed. At 100% relative humidity, the wet-bulb temperature is equal to the air temperature ; at lower humidity the wet-bulb temperature is lower than dry-bulb temperature because of evaporative cooling.
Wood drying reduces the moisture content of wood before its use. When the drying is done in a kiln, the product is known as kiln-dried timber or lumber, whereas air drying is the more traditional method.
Meteorological instruments, including meteorological sensors, are the equipment used to find the state of the atmosphere at a given time. Each science has its own unique sets of laboratory equipment. Meteorology, however, is a science which does not use much laboratory equipment but relies more on on-site observation and remote sensing equipment. In science, an observation, or observable, is an abstract idea that can be measured and for which data can be taken. Rain was one of the first quantities to be measured historically. Two other accurately measured weather-related variables are wind and humidity. Many attempts had been made prior to the 15th century to construct adequate equipment to measure atmospheric variables.
HVAC is a major sub discipline of mechanical engineering. The goal of HVAC design is to balance indoor environmental comfort with other factors such as installation cost, ease of maintenance, and energy efficiency. The discipline of HVAC includes a large number of specialized terms and acronyms, many of which are summarized in this glossary.
Water activity (aw) is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science, the standard state is most often defined as pure water at the same temperature. Using this particular definition, pure distilled water has a water activity of exactly one. Water activity is the thermodynamic activity of water as solvent and the relative humidity of the surrounding air after equilibration. As temperature increases, aw typically increases, except in some products with crystalline salt or sugar.
Steaming or artificial humidity was the process of injecting steam from boilers into cotton weaving sheds in Lancashire, England, in the late 19th and early 20th centuries. The intention was to prevent breakages in short-staple Indian Surat cotton which was introduced in 1862 during a blockade of American cotton at the time of the American Civil War. There was considerable concern about the health implications of steaming. Believed to cause ill health, this practice became the subject of much campaigning and investigation from the 1880s to the 1920s. A number of Acts of Parliament imposed modifications.
This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields.
A backdoor cold front, or backdoor front, is a cold front moving south or southwest along the northeast of the Atlantic seaboard in North America, particularly in the Northeastern United States and the Great Lakes. Typically occurring in spring, the front drives cool Atlantic air from the east or northeast into northeastern US that supersedes the warmer continental air. The front is termed "backdoor" because it arrives from the east, meaning it originates from the opposite direction of a typical cold front and therefore comes through the region's "back door."
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