HOW ELECTIC BULBS ARE MADE

CFL BULBS

• How Arc Lamps Work
  A carbon arc lamp works by hooking two carbon rods to a source of electricity. With the other ends of the rods spaced at the right distance, electrical current will flow through an "arc" of vaporizing carbon creating an intense white light.

All arc lamps use current running through different kinds of gas plasma. A.E. Becquerel of France theorized about the fluorescent lamp in 1857. Low pressure arc lights use a big tube of low pressure gas plasma and include: fluorescent lights and neon signs.

First Electric Incandescent Lamps

Sir Joseph Swann of England and Thomas Edison both invented the first electric incandescent lamps during the 1870s.

•  How Incandescent Lamps Work
  Incandescent lightbulbs work in this way: electricity flows through the filament that is inside the bulb; the filament has resistance to the electricity; the resistance makes the filament heat to a high temperature; the heated filament then radiates light. All incandescent lamps work by using a physical filament.

Thomas A. Edison's lamp became the first commercially successful incandescent lamp (circa 1879). Edison received U.S. Patent 223,898 for his incandescent lamp in 1880. Incandescent lamps are still in regularly use in our homes, today.

• Lightbulbs

Contrary to popular belief, Thomas Alva Edison did not "invent" the first lightbulb, but rather he improved upon a 50-year-old idea. For example: two inventors that patented an incandescent lightbulb before Thomas Edison did were Henry Woodward and Matthew Evan. According to the National Research Council of Canada:

"Henry Woodward of Toronto, who along with Matthew Evans patented a light bulb in 1875. Unfortunately, the two entrepreneurs could not raise the financing to commercialize their invention. The enterprising American Thomas Edison, who had been working on the same idea, bought the rights to their patent. Capital was not a problem for Edison: he had the backing of a syndicate of industrial interests with $50,000 to invest - a sizable sum at the time. Using lower current, a small carbonized filament, and an improved vacuum inside the globe, Edison successfully demonstrated the light bulb in 1879 and, as they say, the rest is history."

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HOW GOLD CHAINS ARE MADE

A Brief History of Gold

Who discovered gold

A child finds a shiny rock in a creek, thousands of years ago, and the human race is introduced to gold for the first time.

Gold was first discovered as shining, yellow nuggets. "Gold is where you find it," so the saying goes, and gold was first discovered in its natural state, in streams all over the world. No doubt it was the first metal known to early hominids.

Gold became a part of every human culture. Its brilliance, natural beauty, and luster, and its great malleability and resistance to tarnish made it enjoyable to work and play with.

Where does gold come from ?

     Because gold is dispersed widely throughout the geologic world, its discovery occurred to many different groups in many different locales. And nearly everyone who found it was impressed with it, and so was the developing culture in which they lived.

    Gold was the first metal widely known to our species. When thinking about the historical progress of technology, we consider the development of iron and copper-working as the greatest contributions to our species' economic and cultural progress - but gold came first.

Gold is the easiest of the metals to work. It occurs in a virtually pure and workable state, whereas most other metals tend to be found in ore-bodies that pose some difficulty in smelting. Gold's early uses were no doubt ornamental, and its brilliance and permanence (it neither corrodes nor tarnishes) linked it to deities and royalty in early civilizations . 

Gold has always been powerful stuff. The earliest history of human interaction with gold is long lost to us, but its association with the gods, with immortality, and with wealth itself are common to many cultures throughout the world.

Early civilizations equated gold with gods and rulers, and gold was sought in their name and dedicated to their glorification. Humans almost intuitively place a high value on gold, equating it with power, beauty, and the cultural elite. And since gold is widely distributed all over the globe, we find this same thinking about gold throughout ancient and modern civilizations everywhere.

     Gold, beauty, and power have always gone together. Gold in ancient times was made into shrines and idols ("the Golden Calf"), plates, cups, vases and vessels of all kinds, and of course, jewelry for personal adornment.

 

     The "Gold of Troy" treasure hoard, excavated in Turkey and dating to the era 2450 -2600 B.C., show the range of gold-work from delicate jewelry to a gold gravy boat weighing a full troy pound. This was a time when gold was highly valued, but had not yet become money itself. Rather, it was owned by the powerful and well-connected, or made into objects of worship, or used to decorate sacred locations.

    Gold has always had value to humans, even before it was money. This is demonstrated by the extraordinary efforts made to obtain it. Prospecting for gold was a worldwide effort going back thousands of years, even before the first money in the form of gold coins appeared about 700 B.C.

In the quest for gold by the Phoenicians, Egyptians, Indians, Hittites, Chinese, and others, prisoners of war were sent to work the mines, as were slaves and criminals. And this happened during a time when gold had no value as 'money,' but was just considered a desirable commodity in and of itself.

     The 'value' of gold was accepted all over the world. Today, as in ancient times, the intrinsic appeal of gold itself has that universal appeal to humans. But how did gold come to be a commodity, a measurable unit of value?

    Gold, measured out, became money. Gold's beauty, scarcity, unique density (no other metal outside the platinum group is as heavy), and the ease by which it could be melted, formed, and measured made it a natural trading medium. Gold gave rise to the concept of money itself: portable, private, and permanent. Gold (and silver) in standardized coins came to replace barter arrangements, and made trade in the Classic period much easier.

     Gold was money in ancient Greece. The Greeks mined for gold throughout the Mediterranean and Middle East regions by 550 B.C., and both Plato and Aristotle wrote about gold and had theories about its origins. Gold was associated with water (logical, since most of it was found in streams), and it was supposed that gold was a particularly dense combination of water and sunlight.

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HOW TO MAKE A PENCIL

The History of the Pencil

                  The earliest writing implements were small brushes made from plants, and the modern word "pencil" itself comes from the Latin word penicillus, which means "little tail" or "little brush." The ancient Greeks and Romans first used little pieces of lead as writing implements, and that very early use of lead is why we still use the term "lead pencil" even though pencils have not contained lead since the 1500's. Writing implements made from sticks of graphite were developed after a huge graphite deposit was discovered in England in 1564.

                      The first pencils using a stick of graphite enclosed in a wood case were made in Germany, and wood-cased pencils were being mass-produced in Nuremberg by 1662. In 1795, French chemist Nicholas Jacques Conté received a patent for a process of mixing powdered graphite and clay, forming the mixture into sticks, and then hardening them in a furnace that is still in use today.

The first American-made pencils were produced by William Munroe in Concord, Massachusetts, in 1812, but he made his cores from a dried graphite paste that was not hardened and their quality was inferior compared to pencils made in Germany. In 1847, Joseph Dixon established a factory outside New York City that used graphite to manufacture crucibles for melting metals and polish for cast iron stoves from graphite, as well as pencils on a limited scale, but pencils equal in quality to those made in Germany did not begin coming out of America until 1861, when German immigrant Eberhard Faber established a factory in New York City that used the Conté process for producing the cores. Pencils with attached erasers were being made by 1853, and pencils with round cores were first produced by the Joseph Dixon Crucible Company about 1876.

                  Although pencils are now sold in a wide variety of colors, the most common color by far is bright yellow. Manufacturers began painting their pencils yellow in the 1890's because at that time some of the best graphite deposits in the world were in China and companies wanted their customers to know that their pencils were made using the highest quality graphite available; yellow was chosen because that is the color of royalty and respect in traditional Chinese culture.

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