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Hobbies & Science : Society & Culture & Entertainment
Medieval Glassblowing Tools
Glass has been around for 3,500 years, but the technique of blowing it like soap bubbles started in about 50 BCE with the Romans. Glass vessels of the period were blown, while colored glass for church windows was more commonly rolled. The basic tools used by glassblowers then are still used today an
How To Make a Teepee From PVC Pipe
Teepees were a common sight on the American plains, back in the days when the buffalo roamed. Compact, efficient and portable, teepees were a perfect home for nomadic people. Today, they are a symbol of adventure and of a deep bond with nature. Unfortunately, nature isn't always cooperative, and fin
What Protists Are Found on a Rotting Tree?
Protists are members of the taxonomic kingdom Protista. These organisms may be unicellular, multicellular or colonial, but they are all eukaryotes, meaning they all have a true nucleus and require some type of water-based environment to live. They are often categorized into three main groups -- anim
Homemade Gear Cutting Machines
Gears are perhaps one of the most easily recognizable components of machinery. These devices, when linked together, transfer power from one shaft to another, allowing force to move throughout a mechanism. Gears are found in computer disc drives and engines, in clocks and watches and in mills. If you
How to Sharpen a Pocket Knife Quickly
It's common to come across an unexpected situation where a knife would come in handy. Many people carry a pocket knife with them at all times for such occasions. Pocket knives should always be kept sharp to ensure they are ready to use at any time. Over time, it's inevitable that the blade will beco
What Is a Pascal Unit?
A pascal unit is a term used to define a unit of pressure, tensile strength, stress and elasticity (Young's modulus). The term is commonly used in meteorology to describe atmospheric pressure but has other applications to describe pressure on an object. The term is used only in countries that have a
Define Chemical Weathering
Weathering refers to the erosion of rock by mechanical or chemical means through the weather. Mechanical erosion refers to fracturing and abrasion. Chemical weathering is distinguished by its chemical reactions---such as oxidation, hydration, ion exchange and chelation.
Features of Four Different Kinds of Compound Light Microscopes
Zacharias Jansen built one of the earliest compound light microscopes in 1595 by combining two lenses with collapsible tubes to magnify an image up to nine times. Today, compound microscopes can magnify objects up to 1,200 times. Biology classes in high school and college often use the upright compo
About Soil Nematodes
There are thousands of nematodes, or microscopic worms (classified scientifically as round worms), in most plots of soil. In certain forest habitats and agricultural habitats, millions of nematodes may be present in the soil. Some cause diseases in plants, while others benefit the soil and everythin
How to Date Griswold Cast Iron Pans
Griswold Manufacturing, makers of cast iron cookware, started business in Erie, Pennsylvania, about 1865. Wagner Manufacturing, an American competitor for years, purchased Griswold in 1957, so Griswold had 92 years of production in Erie. That is nearly a century of production for collectors to date
Design of Concrete Shear Walls
A concrete shear wall is a structural element designed to resist horizontal, or shear, forces parallel to the plane of the wall. Concrete walls are typically structurally efficient, but become more attractive to building designers when they can withstand shear forces.
How to Replace the Sander Bands on a Dremel Tool
Sanding discs are available in coarse, medium and fine grits for the Dremel. You can use the sanding discs for model making and cabinetry. A drum is also available. The drum sander is good for shaping wood, smoothing glass, sanding inside curves and other tricky sanding. Sanding bands fit onto the d
How to Replace a Peg Perego Battery
Thanks to Peg Perego, many children are able to ride around like grownups on their very own miniature versions of popular vehicles, such as John Deere tractors or Ducati Monster motorcycles. But when the battery dies, what do you do? Buying a whole new battery system from Peg Perego is an option --
Heat Capacity of the Earth
Heat capacity measures how much energy it takes to raise the temperature of a substance or object by a given amount. Calculating the heat capacity of Earth is difficult because there are so many factors to take into account.
How Do They Make Ships in a Bottle?
BasicsThe exact method of getting a ship in a bottle depends upon the proclivities of the person doing the building. One technique is to build the ship on the outside of the bottle, then collapse the masts and the sails before inserting it. The other is to build the ship completely inside...
Silver Oxide Battery Uses
Silver oxide batteries are typically small and rather specialized. They were invented during World War II to meet the military's need for compact power supplies with longer life than the zinc-carbon batteries then available. The silver oxide battery has a long shelf life and can withstand a high dis
What Happens When Acid Rain Falls to the Ground?
Acid rain is defined by rainwater that contains higher than normal amounts of nitrate and sulfuric acids, according to the United states Environmental protection Agency. Acid rain is considered an environmental result of fossil fuel emissions reaching into the atmosphere and becoming trapped in clou
Definition of Staphylococci
Staphylococci is a genus of a group of some 30 species of bacteria, only a few of which are harmful to humans. Staphylococci are named for the bacteria's appearance under a microscope. The term "staph" is used to describe the clusters of cells (like bunches of grapes) that are seen in this genus. "C