Fortifications (Latin fortis, strong, and facere, to make) are militaryconstructions designed for defensivewarfare. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs.
Nakhal Fort, one of the best-preserved forts in Oman. Photographed by Andy Carvin, October 2003.
Many military installations are known as forts, although they are not always fortified. Larger forts may class as fortresses, smaller ones formerly often bore the name of fortalices. The word fortification can also refer to the practice of improving an area's defense with defensive works.
The art of laying out a military camp or constructing a fortification traditionally classes as castrametation, since the time of the Roman legions. The art/science of laying siege to a fortification and of destroying it has the popular name of siegecraft and the formal name of poliorcetics. In some texts this latter term also applies to the art of building a fortification.
Fortification is usually divided into two branches, namely permanent fortification and field fortification. Permanent fortifications are erected at leisure, with all the resources that a state can supply of constructive and mechanical skill, and are built of enduring materials. Field fortifications are extemporized by troops in the field, perhaps assisted by such local labor and tools as may be procurable, and with materials that do not require much preparation, such as earth, brushwood and light timber. There is also an intermediate branch known as semipermanent fortification. This is employed when in the course of a campaign it becomes desirable to protect some locality with the best imitation of permanent defences that can be made in a short time, ample resources and skilled civilian labor being available.
These foods were chosen for fortification with folate because they are staple products for most of the U.S. population, and because they have a long history of being successful vehicles for improving nutrition to reduce the risk of classic nutrient deficiency diseases.
Because FDA has a mandate to set fortification levels that are safe for all population groups, lack of long term data makes it impossible to conclude that continuous intakes of 1 mg or more daily would be safe.
Iodine fortification was initiated in the U.S. in 1924 to prevent goiter, cretinism and other symptoms of severe iodine deficiency.