Wood

The wood is the hard part of the trees that is underneath the crust. According to the type of tree, there are hard wood and soft wood.
The wood is the raw material better used by the man. It is obtained from the trees that conform the Earth forests.
The forests occur in very different climates but all must have sufficient humidity for the development of the trees One is used, in addition, in constructing houses; it is used as stakes to surround earth; in the construction of boats; in domestic utensils (like the "dogs" for the clothes); in vasijas for wine, and thousand different applications. He was one of the materials firstly used by the man. In the Paleolítico the hard wood for arms was already distinguished, axes, thorns, and the light and soft wood for woods and twigs. When the man began to work with metals, they increased the possibilities of the uses of the wood since these allowed their survey and works. In Greece they appear the first own utensils of a carpenter, like the mountain range, we drill, gouge, etc, the first works of stature, bas-relief and the carpentry. Structure of the wood




juegos gratis

Glass...

The Glass is an amorphous substance made primarily of silica (derived from sand, flint, or quartz), fused at high temperatures with borates or phosphates.

It is neither a solid nor a liquid but exists in a vitreous, or glassy, state in which molecular units have disordered arrangement but sufficient cohesion to produce mechanical rigidity. Glass is cooled to a rigid state without the occurrence of crystallization; heat can reconvert glass to a liquid form. Usually transparent, glass can also be translucent or opaque. Color varies with the ingredients of the batch.

Glass was first made before 2000 bc and has since served humans in many ways. It has been used to make useful vessels as well as decorative and ornamental objects, including jewelry. Glass also has architectural and industrial applications.

The Float Process offers to the market of the construction leaves of glass of great size and perfection, not only by its flat completion, but by its low optical distortion and faults. With the use of the glass in remodelings and improvements, the benefits of new products, like the smaller costs of energy, extend to existing buildings. The glass comprises integral of most of the construction projects.
As much the new buildings as the remodeling of existing require great amounts of glass.

The architects look for bring the outside to the interior of the building, and to maximize the natural light. Thus, the areas with glass are more and more ample in facades and ceilings but the remodeling of buildings represents around 40% of the consumption of glass world-wide level.

Introduzca los términos de búsqueda. Envíe el formulario de búsqueda

Iron ´n steel

Metals time line...

Bricks

click here to listen the text:
http://www.geocities.com/polejandro/brick.wav


The brick it´s a hard block used for construction, a rectangular block of clay or a similar material that is baked until it is hard and is used for building houses, walls, and other large permanent structures.

The brick is compared with the stone because its resistance to the time and the fire. It is easy to transport, to produce and to put. Another characteristic of the brick is that it allows to isolate the heat and the sounds.

The bricks can be of different forms and sizes, depending on the use that is wanted to give to it, for example: for the columns are used the bricks with rounded faces and for a walls generally are used the bricks with squared faces...

The proportions between wide and the length of the modern brick usually are approx of 1:2, this with the purpose of allowing a wide variety of bonding patterns, for exam.