The shaping is sometimes accomplished by plastering the soft mass into wooden moulds, as in making bricks.
13.--_Preparation of Peat Fuel by Machinery, etc._
Within the last 15 years, numerous inventions have been made with a view to improving the quality of peat fuel, as well as to expedite its production. These inventions are directed to the following points, viz.: 1. _Condensation_ of the peat, so as bring more fuel into a given space, thus making it capable of giving out an intenser heat; at the same time increasing its hardness and toughness, and rendering it easier and more economical of transportation. 2. _Drying_ by artificial heat or reducing the amount of water from 20 or 25 _per cent._ to half that quantity or less. This exalts the heating power in no inconsiderable degree. 3. _Charring._ Peat-charcoal is as much better than peat, for use where intense heat is required, as wood charcoal is better than wood. 4. _Purifying from useless matters._ Separation of earthy admixtures which are incombustible and hinder draught.
_Pressing Wet Peat._--The condensation of peat was first attempted by subjecting the fresh, wet material, to severe pressure. As long ago as the year 1821, Pernitzsch, in Saxony, prepared peat by this method, and shortly afterwards Lord Willoughby d'Eresby, in Scotland, and others, adopted the same principle. Simple pressure will, indeed, bring fresh peat at once into much smaller bulk; but, if the peat be fibrous and light, and for this reason require condensation, it is also elastic, and, when the pressure is relieved, it acquires again much of its original volume.
Furthermore, although pressure will squeeze out much water from a saturated well-ripened peat, the complete drying of the pressed blocks usually requires as much or more time than that of the unpressed material, on account of the closeness of texture of the surface produced by the pressure.
The advantages of subjecting fresh peat to pressure in the ordinary presses, it is found, are more than offset by the expense of the operation, and it is therefore unnecessary to give the subject further attention.
Fresh peat appears however to have been advantageously pressed by other mechanical means. Two methods require notice.