a April, 1908. J 



Wood Distillation. 



are used in some countries to also obtain wood tars. In no case, however, 

 can the gaseous products be secured. To obtain these and the solid and 

 liquid products economically, retorts with the requisite condensing ar- 

 rangements are required. Wood consists mainlv of cellulo'Se or woodv 

 fibre, and plant juice or sap. These are composed of carbon, hydrogen, 

 oxygen, nitrogen, and a small amount of mineral matter. Under the in- 

 fluence of heat in the absence of air, that is, in a closed vessel or retort 

 the cellulose and other matters are broken up, and new compounds formed, 

 'lepending upon the degree of heat and the rapidity with which it is brought 

 to bear on the vessel ; a great deal also depends upon the care and skill 

 used in a])pl\ing I'he heat to the retorts. 



The works themselves consist of a large shed for stacking the cut tim- 

 ber to permit of thorough drying, an operation occupying 6 to 12 months; 

 .etort and condensing house ; lab'iratorv and the usual residential buildings. 



ONE OF THE COOLING CHAMBERS. 



The timber is brought down on the tramway, stacked, and, when sufficiently 

 drv, that is, with olily some 10 per cent, of moisture, it is loaded on to 

 trucks holding 3 tons each of green wood, equivalent, when dry, to a little 

 over 2 tons. Four of these trucks consntute one charge for a retort, ag- 

 gregating some 9 tons of dry wood. The trucks are run on to a cage-like 

 traverser on rails, which is shaped to almost exactly fill the retort. The 

 latter is a cylinder 46 feet in length, set in brick work like a boiler and 

 lieated in the same manner. Opposite to the retorts are the cooling cham- 

 bers. These are identical in size and construction with the retorts, except 

 that they are not built in. After the operation of distilling is complete, 

 the door of the retort is opened and the traverser, a cage full of red 

 hot charcoal, is rapidlv run across into cooling chambers, and the doors 

 closed to prevent the charcoal burning away in contact with the air. Sireams 

 of water play on the chambers to hasten the cooling process. 



