The French use the word chateau for castle but it used to cover both: the Chateau-Gaillard, a fortress of the 12th century; and the manors dating from the 12th to the 18th century, which have no or little defensive capability.he French use the word chateau for castle but it used to cover both: the Chateau-Gaillard, a fortress of the 12th century; and the manors dating from the 12th to the 18th century, which have no or little defensive capability.
Hydrate, any compound containing water in the form of H2O molecules, usually, but not always, with a definite content of water by weight. The best-known hydrates are crystalline solids that lose their fundamental structures upon removal of the bound water.
Methane hydrate is a crystalline solid that consists of a methane molecule surrounded by a cage of interlocking water molecules (see image at top right). Methane hydrate is an  ice  that only occurs naturally in subsurface deposits where temperature and pressure conditions are favorable for its formation.he most likely methane hydrate deposits to be selected for first development will have the following characteristics: 1) high concentrations of hydrate; 2) reservoir rocks with high permeability; and, 3) locations where there is an existing infrastructure.