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Chalkboard Eraser
A chalkboard eraser (sometimes known as a duster in India ) is a special type of eraser specifically used to erase chalk markings on slating paint (used on chalkboards and slates). It is most commonly made of felt strips attached to a handle. Chalkboard erasers are typically broad and rectangular, intended to clear large areas for new content as part of a lecture or presentation. History Chalkboard erasers were invented around 1863 by John L. Hammett, who owned some stores that sold and created school products in Rhode Island and then later in Boston. Mostly slates were sold there as well as chalk and so on. At the time, rags or old cloths were used to erase and get rid of the chalk markings on slates in schools, offices, and for the most part, everywhere. Hammett created the chalkboard before the invention of the chalkboard eraser by creating ''slating paint''. Hammett then, during a presentation on his chalkboard "discovered" that wool felt strips wiped off the chalk writing be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalkboard Eraser, Waldorf School, East Lexington MA
A blackboard or a chalkboard is a reusable writing surface on which text or drawings are made with sticks of calcium sulphate or calcium carbonate, better known as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. Design A blackboard can simply be a board painted with a dark matte (surface), matte paint (usually black, occasionally dark green). Matte black plastic sign material (known as closed-cell PVC foamboard) is also used to create custom chalkboard art. Blackboards on an A-frame are used by restaurants and bars to advertise daily specials. Adhesive chalkboard surface is also available in stores as rolls of textured black plastic shelf covering, which is applied to the desired wall, door or other surface. A more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade blackboards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eraser
An eraser (also known as a rubber in some Commonwealth countries, including South Africa from which the material first used got its name) is an article of stationery that is used for removing marks from paper or skin (e.g. parchment or vellum). Erasers have a rubbery consistency and come in a variety of shapes, sizes, and colors. Some pencils have an eraser on one end. Less expensive erasers are made from synthetic rubber and synthetic soy-based gum, but more expensive or specialized erasers are made from vinyl, plastic, or gum-like materials. At first, erasers were invented to erase mistakes made with a pencil; later, more abrasive ink erasers were introduced. The term is also used for things that remove marks from chalkboards and whiteboards. History Before rubber erasers used today, tablets of wax were used to erase lead or charcoal marks from paper. Bits of rough stone such as sandstone or pumice were used to remove small errors from parchment or papyrus documents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalk
Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel. Chalk is mined for use in industry, such as for quicklime, bricks and builder's putty, and in agriculture, for raising pH in soils with high acidity. It is also used for " blackboard chalk" for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals, or gypsum. Description Chalk is a fine-textured, earthy type of limestone distinguished by its light colour, softness, and high porosity. It is composed mostly of tiny fragments of the calcite shells or sk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalkboard
A blackboard or a chalkboard is a reusable writing surface on which text or drawings are made with sticks of calcium sulphate or calcium carbonate, better known as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. Design A blackboard can simply be a board painted with a dark matte (surface), matte paint (usually black, occasionally dark green). Matte black plastic sign material (known as closed-cell PVC foamboard) is also used to create custom chalkboard art. Blackboards on an A-frame are used by restaurants and bars to advertise daily specials. Adhesive chalkboard surface is also available in stores as rolls of textured black plastic shelf covering, which is applied to the desired wall, door or other surface. A more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade blackboards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slate (writing)
A slate is a thin piece of hard flat material, historically slate stone, which is used as a medium for writing on. Writing on a slate is impermanent and easily erased, and the same slate is then reused. Usage The writing slate consisted of a piece of slate, typically either 4x6 inches or 7x10 inches, encased in a wooden frame. Split slate was prepared by scraping with a steel edge, grinding with a flat stone and, finally, polishing with a mix of slate powder in water. Pencils were of a softer stone, such as shale, chalk or soapstone. In 1853 Charles Goodyear patented a compound of hard-vulcanised rubber with powdered porcelain, from which to make white pencils for writing on slates. Usually, a piece of cloth or slate sponge, sometimes attached with a string to the bottom of the writing slate, was used to erase it for reuse. History The exact origins of the writing slate remain unclear. References to its use can be found in the fourteenth century and evidence suggests t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felt
Felt is a textile that is produced by matting, condensing, and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic fiber, acrylic or acrylonitrile or wood pulp–based rayon. Blended fibers are also common. Natural fiber felt has special properties that allow it to be used for a wide variety of purposes. It is "fire-retardant and self-extinguishing; it dampens vibration and absorbs sound; and it can hold large amounts of fluid without feeling wet..." History Felt from wool is one of the oldest known textiles. Many cultures have legends about the origins of felt-making. Sumerian legend claims that the secret of feltmaking was discovered by Urnamman of Lagash. The story of Clement of Metz, Saint Clement and Saint Christopher relates that the men packed their sandals with wool to prevent blisters while fleeing from persecution. At the end of their journey the movement and sweat had turned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhode Island
Rhode Island ( ) is a state in the New England region of the Northeastern United States. It borders Connecticut to its west; Massachusetts to its north and east; and the Atlantic Ocean to its south via Rhode Island Sound and Block Island Sound; and shares a small maritime border with New York, east of Long Island. Rhode Island is the smallest U.S. state by area and the seventh-least populous, with slightly more than 1.1 million residents . The state's population, however, has continually recorded growth in every decennial census since 1790, and it is the second-most densely populated state after New Jersey. The state takes its name from the eponymous island, though most of its land area is on the mainland. Providence is its capital and most populous city. Native Americans lived around Narragansett Bay before English settlers began arriving in the early 17th century. Rhode Island was unique among the Thirteen British Colonies in having been founded by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston
Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeastern United States. It has an area of and a population of 675,647 as of the 2020 United States census, 2020 census, making it the third-largest city in the Northeastern United States after New York City and Philadelphia. The larger Greater Boston metropolitan statistical area has a population of 4.9 million as of 2023, making it the largest metropolitan area in New England and the Metropolitan statistical area, eleventh-largest in the United States. Boston was founded on Shawmut Peninsula in 1630 by English Puritans, Puritan settlers, who named the city after the market town of Boston, Lincolnshire in England. During the American Revolution and American Revolutionary War, Revolutionary War, Boston was home to several seminal events, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wool
Wool is the textile fiber obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have some properties similar to animal wool. As an animal fiber, wool consists of protein together with a small percentage of lipids. This makes it chemically quite distinct from cotton and other plant fibers, which are mainly cellulose. Characteristics Wool is produced by follicles which are small cells located in the skin. These follicles are located in the upper layer of the skin called the epidermis and push down into the second skin layer called the dermis as the wool fibers grow. Follicles can be classed as either primary or secondary follicles. Primary follicles produce three types of fiber: kemp, medullated fibers, and true wool fibers. Secondary follicles only produce true wool fibers. Medullated fibers share nearly identical characteristics to hair and are long but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
School
A school is the educational institution (and, in the case of in-person learning, the Educational architecture, building) designed to provide learning environments for the teaching of students, usually under the direction of teachers. Most countries have systems of formal education, which is sometimes compulsory education, compulsory. In these systems, students progress through a series of schools that can be built and operated by both government and private organization. The names for these schools vary by country (discussed in the ''School#Regional terms, Regional terms'' section below) but generally include primary school for young children and secondary school for teenagers who have completed primary education. An institution where higher education is taught is commonly called a university college or university. In addition to these core schools, students in a given country may also attend schools before and after primary (elementary in the U.S.) and secondary (middle scho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is drained through a fine mesh leaving the fibre evenly distributed on the surface, it can be pressed and dried. The papermaking process developed in east Asia, probably China, at least as early as 105 Common Era, CE, by the Han Dynasty, Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. Although paper was originally made in single sheets by hand, today it is mass-produced on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and Housekeeping, cleaning. It may also be used a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eraser
An eraser (also known as a rubber in some Commonwealth countries, including South Africa from which the material first used got its name) is an article of stationery that is used for removing marks from paper or skin (e.g. parchment or vellum). Erasers have a rubbery consistency and come in a variety of shapes, sizes, and colors. Some pencils have an eraser on one end. Less expensive erasers are made from synthetic rubber and synthetic soy-based gum, but more expensive or specialized erasers are made from vinyl, plastic, or gum-like materials. At first, erasers were invented to erase mistakes made with a pencil; later, more abrasive ink erasers were introduced. The term is also used for things that remove marks from chalkboards and whiteboards. History Before rubber erasers used today, tablets of wax were used to erase lead or charcoal marks from paper. Bits of rough stone such as sandstone or pumice were used to remove small errors from parchment or papyrus documents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
