The methods of condensing peat, that remain to be described, are based upon radically different principles from those already noticed. In these, little or no pressure is employed in the operations; but advantage is taken of the important fact that when wet or moist peat is ground, cut or in any way reduced to a pulpy or pasty consistence, with destruction of the elastic fibres, it will, on drying, shrink together to a coherent mass, that may acquire a density and toughness much greater than it is possible to obtain by any amount of mere pressure. The various processes that remain to notice are essentially reducible to two types, of which the French method, invented by Challeton, and the German, invented it appears by Weber, are the original representatives. The former method is only applicable to earthy, well-decomposed peat, containing little fibre. The latter was originally applied to fibrous moss-peat, but has since been adapted to all kinds. Other inventors, English, German, and American, have modified these methods in their details, or in the construction of the requisite machinery, rendering them more perfect in their execution and perhaps more profitable in their results; but, as regards the essential principles of production, or the quality of product, no advance appears to have been made beyond the original inventors. a. _Condensation of Earthy Peat._ _Challeton's Method_ consists essentially in destroying the fibres, and reducing the peat by cutting and grinding with water to a pulp; then slowly removing the liquid, until the peat dries away to a hard coherent mass. It provides also for the purification of the peat from earthy matters. It is, in many respects, an imitation of the old Dutch and Irish mode of making "hand peat" (_Baggertorf_), and is very like the paper manufacture in its operations. Challeton's Works, situated near Paris, at Mennecy, near Montanges, were visited in 1856 by a Commission of the Agricultural Society of Holstein, consisting of Drs. Meyn and Luetkens, and also by Dr. Ruehlmann, in the interest of the Hanoverian Government. From their account[22] the following statements are derived.