58 EXPLOITATION OF THE MARITIME PINE. 



" In choosing a site for a furnace, the position of the timber to be 

 used should be considered. A central position is best, so as to 

 diminish the expense of land carriage. The ground is first levelled, 

 and all heath and shrubs removed to prevent the chance of fire. 

 The maritime pine is easily injured by the heat and smoke of a 

 furnace, and it is best to place the kiln either outside the forest or 

 else in the centre of a considerable clearing, as dead trees become a 

 nursery of insects destructive to trees. 



" Where old sites are conveniently situated, it is a good plan to 

 make choice of these. 



" When a new furnace is made the first bed should be laid on a 

 layer of horizontal branches. This is called a plancher, a platform or 

 floor. 



"The size of the furnace varies according as the charcoal is for 

 domestic or for other uses. 



"For kitchen use, experts recommend that 15 or 18 steres or 

 cubic meters of wood should be burned at a time, and 30 or 35 

 when it is to be used in forges. Small furnaces occasion less waste, 

 but sometimes they are apt to fail. 



" The site of the furnace being prepared, a large post is placed 

 vertically in the centre, the wood to be carbonised is placed round it 

 after its being surrounded by twigs and dry wood which will ignite 

 easily ; the faggots are placed on end, but inclining gently ; the first 

 layer being made, a second, third, and fourth are added. In doing 

 this the largest and greenest pieces are used for the lowest and most 

 central part of the furnace, because there the fire burns most fiercely. 

 The small dry pieces are placed on the outside and top of the mass. 

 The faggots should be pressed closely together, and the interstices 

 filled with twigs. If several kinds of wood are used at once, the 

 hardest should be placed in the centre. 



"The cone completed, the central post is withdrawn, and this 

 leaves a chimney in the centre, the whole is then covered with leaves, 

 twigs, earth, and moss, more or less mixed with sand. This layer of 

 earth should be 5 or 6 centimetres thick. Fire is then set to the 

 lower part of the chimney, which remains open a certain time so that 

 the mass may be ignited. The chief fire is thus in the middle of the 

 chimney, and the workman takes care to feed it with wood when a 

 vacancy is produced. Whenever the mass is sufficiently ignited, the 

 opening is stopped, the moment for doing this is regulated by the 

 colour of the smoke, which, white at first, becomes blue and 

 transparent when the flames acquire strength. The entrance and 



