### keystone

(Learning Modules / Mathematics / Bridges) The 'keystone' is the central stone in an arch, and begins the distribution of the vertical 'load' forces down and around the arch. The keystone is the last voussoir to be placed in position, and allows each half of the arch to support the other.

### keystone

A stone cut the shape of a keystone in an arch. Keystones are usually step cut.
Found on http://www.encyclo.co.uk/local/22290

### Keystone

The Keystone is the central wedge-shaped stone at the top of a curved arch that holds the arch in place. The keystone is also known as the central voussoir.
Found on http://www.designbuild-network.com/glossary/keystone.html

### Keystone

• (n.) The central or topmost stone of an arch. This in some styles is made different in size from the other voussoirs, or projects, or is decorated with carving. See Illust. of Arch.
Found on http://thinkexist.com/dictionary/meaning/keystone/

### keystone

(from the article `arch`) ...blocks are called voussoirs. Each voussoir must be precisely cut so that it presses firmly against the surface of neighbouring blocks and conducts ...
Found on http://www.britannica.com/eb/a-z/k/25

### keystone

key 3 headstone noun the central building block at the top of an arch or vault
Found on https://www.encyclo.co.uk/local/20974

### Keystone

[architecture] A keystone is the wedge-shaped stone piece at the apex of a masonry vault or arch, which is the final piece placed during construction and locks all the stones into position, allowing the arch to bear weight. Although a masonry arch or vault cannot be self-supporting until the keystone is placed, the keystone experiences the ...
Found on http://en.wikipedia.org/wiki/Keystone_(architecture)

### Keystone

[Berkeley, California] The Keystone, also known as Keystone Berkeley, was a small music club in Berkeley, California, which operated in the 1970s and 1980s. Numerous nationally known groups performed there, and the club was a regular venue for the Jerry Garcia Band. ==Albums recorded at Keystone== ...
Found on http://en.wikipedia.org/wiki/Keystone_(Berkeley,_California)

### Keystone

[cask] A keystone is a small wooden or plastic fitting used in ale casks. For some years wooden casks have been effectively obsolete, with the majority now being aluminium or stainless steel, and a few sturdy plastic ones beginning to appear. Nevertheless, the standard tap is still designed to be hammered into yielding material, punching a ...

### Keystone

[gasoline automobile] The Keystone was an American automobile manufactured from 1914 until 1915. Designed by Chas C. Snodgrass and built in Pittsburgh, it ran using a Rutenber 55 hp six engine. It was built on a 138 inch wheelbase. ...
Found on http://en.wikipedia.org/wiki/Keystone_(gasoline_automobile)

### Keystone

[limestone] Keystone is a type of limestone, or coral rag, quarried in the Florida Keys, in particular from Windley Key fossil quarry, which is now a State Park of Florida. The limestone is Pleistocene in age, and the rock primarily consists of scleractinian coral, such as Elkhorn coral and Brain coral. The Hurricane Monument, commemorating...
Found on http://en.wikipedia.org/wiki/Keystone_(limestone)

### Keystone

[steam automobile] The Keystone Steamer was an American automobile manufactured from 1899 until 1900 in Lebanon, Pennsylvania. Manufacturer was the Keystone Match & Machine Company, founded in 1894 and offering bicycles from 1896. In 1899 the company offered an interesting but complicated steam car. It featured runabout coachwork and was po...
Found on http://en.wikipedia.org/wiki/Keystone_(steam_automobile)

### Keystone

[train] == Design == The coaches were of a unique, split-level design, with the center portion of each car having a floor level two feet below that of standard coaches. This lowered the cars` center of gravity, allowing the train to safely take curves at higher speeds. The coaches were also built to a stressed-skin `Tubular` design, with th...
Found on http://en.wikipedia.org/wiki/Keystone_(train)

### Keystone

Key'stone` noun (Architecture) The central or topmost stone of an arch. This in some styles is made different in size from the other voussoirs, or projects, or is decorated with carving. See Illust. of Arch . Keystone State , the State of Pennsylvania; - - so called fro...
Found on http://www.encyclo.co.uk/webster/K/7

### Keystone

a central stone at the summit of an arch, locking the whole together.
Found on http://www.translationdirectory.com/glossaries/glossary336.php

### Keystone

A form of video image distortion in which the top of the picture is wider than the bottom, or the left is taller than the right, or vice versa. The image is shaped like a trapezoid rather than a rectangle.
Found on http://www.encyclo.co.uk/local/21058

### Keystone

Central wedge in top of arch.
Found on http://www.castlesontheweb.com/glossary.html

### Keystone

Central wedge in top of arch.
Found on http://www.encyclo.co.uk/local/20018

### keystone

central wedge shaped stone at the top of an arch
Found on http://www.castles-of-britain.com/glossary.htm

### Keystone

Final, or first stone, that is used to lock together a section of stonework, or provide a firm base stone e.g. in pitching or revetments.
Found on http://www.encyclo.co.uk/local/20717

### Keystone

Founded in 1912 when financing was received by Mack Sennett, Keystone Company began producing films in 1913. Five hundred films were made under the leadership of Sennett and included such stars as Charlie Chaplin, Chester Conklin, Fatty Arbuckle, and Buster Keaton. Though it did not survive the departure of Sennett in 1917 it became known for what ...
Found on http://www.allmovie.com/glossary/term/keystone

### Keystone

In architecture a keystone is the central or topmost stone of an arch. This in some styles is made different in size from the other voussoirs, or projects, or is decorated with carving.
Found on http://www.probertencyclopaedia.com/browse/TK.HTM

### Keystone

In stonework the keystone is a central voussoir that is quite often decorated in some way. When the arch is being built it is always built up evenly from side to side and the last stone placed is the keystone.;
Found on http://www.encyclo.co.uk/local/22188

### Keystone

Stone forming the top of an arch.
Found on http://www.translationdirectory.com/glossaries/glossary235.php

### Keystone

the architectural piece at the crown of a vault or arch and marks its apex, locking the other pieces into position.
Found on http://en.wikipedia.org/wiki/Glossary_of_architecture
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