History of pencil
The use of lead and graphite has been started since the Greeks. Both give the effect of gray streaks, although graphite is a little more black. Graphite is very rarely used until later on in 1564 discovered a pure graphite content in large numbers in Borrowdale, a valley in the Lake District, northern England. Although looks like coal, minerals can not be burned, and shiny black scars, and easily removed on the surface that can be inscribed.
At this time the term graphite is still confused with tin, lead, and Plumbago, meaning "like lead" given its almost the same. Therefore, the term lead pencil (pencil lead) is still in use today. Because the texture is oily, chunks of lamb wrapped in leather or a small piece of tin berbentuktongkat bandaged with a rope. No one knows who first had the idea to insert a black tin timber into the container, but in 1560's, a primitive pencil had reached the European continent.
Shortly thereafter, lead mined and exported to meet the demands of the artists, and in the 17th century, to say the lead has been used everywhere. At the same time, the makers to experiment with black lead pencil to produce better writing instruments. Because pure and easily extracted, lead from Borrowdale to be the target thieves and black marketeers. To overcome this, the British Parliament passed a law in 1752 which stipulates that could lead thief jailed or banished to a convict colony.
But in 1779, a chemist Carl W. Scheele researched and concluded that the graphite has a much different chemical properties with lead. Graphite is pure carbon molecule composition software. Finally in 1789, the German geologists, Abraham G. Werner gave the name graphite, which is derived from Greek words graphein, which means writing. Thus, the contents of a pencil rather than tin.
History of eraser
For years, British monopolize the manufacture of graphite pencil because it was pure enough to use without needing to be processed again. Because Europe is less quality graphite, pencil factories there to experiment with various ways to improve the content of a pencil. French engineer Nicolas-Jacques Conté mixing powdered graphite with clay, forming the mixture into sticks, and burned in the fireplace. By varying the ratio of graphite to clay, he can make the contents of a pencil that produces various shades of black, the process used until now.
In the 19th century, the manufacture of pencil manufacture became big business. Graphite is found in several places, including Siberia, Germany, and what is now the Czech Republic. In Germany and then in the United States, a number of factories opened. Mechanisation and mass production the price pressure, and at the beginning of the 20th century, even school children using a pencil.
At first graphite pencils were given the torn wrapping paper as the wearer desires. But later found more practical and efficient way by covering the entire graphite rod with two blades ditoreh wood to make room for graphite shaft and then put together. Pencil sharpener as a complement to stationery. Peraut mechanical pencil whittle simplify the current user.
Pure graphite artist may be preferred due to its more straightforward. But for everyday use, it takes a lower-quality graphite to be more flexible. In 1795, French chemist, Nicolas Jacques Conté, discovered by mixing graphite with clay to produce a better pencil and practical. One of its derivatives are pencil Konte.
Pencil sharpener as a complementary stationery
On March 30, 1858 Hymen Lipman of Philadelphia, Pennsylvania, United States patented the pencil with eraser tip. But then this patent revoked on the grounds sebanenarnya no new invention of the pencil. Peraut mechanic discovered in 1880 and quickly became very popular.
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