Mice/Mouses

November 1, 2009 by · Leave a Comment 

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A small box-shaped device with wheels that is moved about by hand over a flat surface and generates signals to control the position of a cursor or pointer on a computer display.

The most popular pointing device. It was called a “mouse” because it more or less resembled one, with the cord being the tail. Although key commands can often substitute, graphical interfaces (GUIs) are designed for pointing devices. However, graphics applications, such as CAD and image editing, demand a pointing device. On a PC, the mouse connects to the PS/2, USB or serial port.

Mouse movement is relative. The cursor moves from its existing location. The mouse could be moved across your arm, and the screen cursor would move as well. The mouse-like object on a graphics tablet, which is correctly called the “tablet cursor” or “puck” is often not relative. It contacts the tablet with absolute reference. Placing it on the upper left part of the tablet moves the screen cursor to the corresponding location.

After years of use, it is now known that mice can be hazardous to your health. Many applications require endless clicking and dragging, which puts a strain on the wrist.

Invented by Doug Engelbart in the early 1960s at Stanford Research Institute (SRI), it used two moving wheels 90 degrees apart. Most mechanical mice are still made this way, but the wheels are inside, and the ball moves the wheels.

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Wood Burning Stoves

October 22, 2009 by · Leave a Comment 

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As early as Roman times stoves made of clay, tile, or earthenware were in use in central and N Europe. Early Swiss stoves of clay or brick, without chimneys, were built against the outer house wall, with an opening to the outside through which they were fueled and through which the smoke could escape. Scarcity of fuel made an economical heat-retaining device necessary, and these primitive stoves, built of clay, brick, tile, or plastered masonry, became common in the Scandinavian countries, Holland, Germany, and N France. Some exquisitely colored and glazed tile stoves, dating from the 16th and 17th cent., show traces of Moorish influence. In Russia large brick stoves formed a partition between two rooms. Because of the very long flue, which wound back and forth inside the structure, these could be heated for some hours with a small amount of light fuel.

The Franklin stove, invented in 1743 and used for heating, was the lineal descendant of the fireplace, being at first only a portable down-draft iron fireplace that could be set into, or before, the chimney.

It was soon elaborated into what was known as the Pennsylvania fireplace, with a grate and sliding doors. In common use for a period after the Revolution, it was followed by a variety of heaters burning wood and coal. The base burner, or magazine coal heater, was widely used before the general adoption of central heating.

Heating devices that we would call stoves had long been in existence, going back to Roman times. However, the stove as the chief cooking device, taking the place of the fireplace, dates only to around the mid-19th century with the widespread use of wood-burning or coal-burning cooking stoves stove, device used for heating or for cooking food. The stove was long regarded as a cooking device supplementary to the fireplace, near which it stood; its stovepipe led into the fireplace chimney. It was not until about the middle of the 19th cent., when the coal-burning range with removable lids came into general use, that the fireplace was finally supplanted as the chief cooking agency.

A cast-iron stove made in China before A.D. 200 has been found, but it was not until late in the 15th cent. that cast-iron stoves were first made in Europe. These consisted of plates that were grooved to fit together in the shape of a box. Probably the earliest of this type were earthenware stoves enclosed in iron castings decorated with biblical scenes and armorial and arabesque designs. They often bore inscriptions in Norse, German, Dutch, French, or sometimes Latin, and some were dated. Many were highly artistic specimens of handicraft. A typical early iron stove is the wall-jamb, or five-plate, stove, which was fueled from an adjoining room.

Dutch, Swedish, and German settlers of the American colonies, especially those of Delaware, Pennsylvania, and New Jersey, brought with them five-plate stoves or molds for casting them. Iron founding began c.1724 in America, and old forges or foundries have left records of five-plate stoves sold in 1728 as Dutch stoves or, less commonly, carved stoves. These continued to be made until Revolutionary times, when they were superseded by the English, or 10-plate, stove, which stood free of the wall and had a draft or fuel door. These 10-plate devices could cook and warm at the same time and replaced, in part, the large masonry baking oven, usually built outside the house.

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