The peat-cake separates well from the press-cloths; but the pores of the latter become somewhat choked by fine particles that penetrate them. They are therefore washed at each revolution by passing before a pipe from which issue, against them, a number of jets of water under high pressure. The blocks, after leaving the machine, are soft, and require 5 or 6 days to become air-dry. When dry they are dense and of good quality, but not better than the same raw material yields by simple moulding. The capacity of the rolls, which easily turn out 100,000 peats in 24 hours, greatly exceeds at present that of the drying arrangements, and for this reason the works are not, as yet, remunerative. The rolls are, in reality, a simple forming machine. The pressure they exert on the peat, is but inconsiderable, owing to its soft pasty character; and since the pair of rolls costs $8000 and can only be worked 3 to 4 months, this method must be regarded rather as an ingenious and instructive essay in the art of making peat-fuel, than as a practical success. The persevering efforts of the inventor may yet overcome all difficulties and prove the complete efficacy of the method. It is especially important, that blocks of greater thickness should be produced, since those now made, pack together too closely in the fire.
_Neustadt Method._--At Neustadt, in Hanover, a loose-textured fibrous peat was prepared for metallurgical use in 1860, by passing through iron rolls of ordinary construction. The peat was thereby reduced two-thirds in bulk, burned more regularly, gave a coherent coal, and withstood carriage better. The peat was, however, first cut into sods of regular size, and these were fed into the rollers by boys.
Some kinds of peat, when in the air-dry and pulverized state, yield by great pressure very firm, excellent, and economical fuel.
_Lithuanian Process._--In Lithuania, according to Leo,[20] the following method is extensively adopted. The bog is drained, the surface moss or grass-turf and roots are removed, and then the peat is broken up by a simple spade-plow, in furrows 2 inches wide and 8 or 10 inches deep. The broken peat is repeatedly traversed with wooden harrows, and is thus pulverized and dried. When suitably dry, it is carried to a magazine, where it is rammed into moulds by a simple stamp of two hundred pounds weight. The broken peat is reduced to two-fifths its first bulk, and the blocks thus formed are so hard, as to admit of cutting with a saw or ax without fracture. They require no further drying, are of a deep-brown color, with lustrous surfaces, and their preparation may go on in winter with the stock of broken peat, which is accumulated in the favorable weather of summer. In this manufacture there is no waste of material.