The difference in weight between fresh and dry peat is even greater. Fibrous peat, fresh from the bog, may contain ninety _per cent._ of water, of which seventy _per cent._ must evaporate before it can be called dry. The proportion of water in earthy or pitchy peat is indeed less; but the quantity is always large, so that from five to nine hundred weight of fresh peat must be lifted in order to make one hundred weight of dry fuel. 8.--_Time of excavation, and drying._ Peat which is intended to be used after simply drying, must be excavated so early in the season that it shall become dry before frosty weather arrives: because, if frozen when wet, its coherence is destroyed, and on thawing it falls to a powder useless for fuel. Peat must be dried with certain precautions. If a block of fresh peat be exposed to hot sunshine, it dries and shrinks on the surface much more rapidly than within: as a consequence it cracks, loses its coherence, and the block is easily broken, or of itself falls to pieces. In Europe, it is indeed customary to dry peat without shelter, the loss by too rapid drying not being greater than the expense of building and maintaining drying sheds. There however the sun is not as intense, nor the air nearly so dry, as it is here. Even there, the occurrence of an unusually hot summer, causes great loss. In our climate, some shelter would be commonly essential unless the peat be dug early in the spring, so as to lose the larger share of its water before the hot weather; or, as would be best of all, in the autumn late enough to escape the heat, but early enough to ensure such dryness as would prevent damage by frost. The peculiarities of climate must decide the time of excavating and the question of shelter. The point in drying peat is to make it lose its water gradually and regularly, so that the inside of each block shall dry nearly as fast as the outside. Some of the methods of hot-drying peat, will be subsequently noticed. Summer or fall digging would be always advantageous on account of the swamps being then most free from water. In Bavaria, peat is dug mostly in July and the first half of August. 9.--_Drainage._ When it is intended to raise peat fuel _in the form of blocks_, the bog should be drained no more rapidly than it is excavated. Peat, which is to be worth cutting in the spring, must be covered with water during the winter, else it is pulverized by the frost. So, too, it must be protected against drying away and losing its coherency in summer, by being kept sufficiently impregnated with water. In case an extensive bog is to be drained to facilitate the cutting out of the peat for use as fuel, the canals that carry off the water from the parts which are excavating, should be so constructed, that on the approach of cold weather, the remaining peat may be flooded again to the usual height.