134 CARBONIZATION OF TURF. 



Charcoal. The last result is a fixed black substance, tolerably homo- 



geneous, and weighing more than an equal bulk of charred 

 wood. Frequently, in consequence of the sand, the oxide 

 of iron, and the compactness acquired by the previous 

 compression, this substance is the true charcoal of turf; 

 which sometimes, before it is obtained, furnishes a certain 

 quantity of sulphurous acid, arising from the combustion 

 of the sulphur and sulphate of iron contained in such turf 

 as I have dug. This justifies to a certain degree the com- 

 plaints of persons, who refuse to make use of this com- 

 bustible; but this slight defect may be removed by very 

 easy means, which I employ in burning turf in rooms, 

 and of which I shall give the particulars hereafter. 



I shall now give a description of my apparatus, which I 

 shall divide into two parts ; the first describing the furnace r 

 the second the interior part, which I call thcrmolampiQ. 



The furnace is square, terminating above in an arch; 

 and in the front appear three apertures, one over another. 



Its inferior part, in which is the ash-hole, is shaped in- 

 teriorly like a wedge, the base of which is the aperture, 

 one of the square sides lying uppermost and horizontally, 

 the other, an inclined plane, forming the bottom. This 

 form prevents any ashes from lodging in it to obstruct tho 

 fire, and renders the current of air more rapid. It is 

 obvious that the upper part of this ash-hole is formed bv 

 the grate, which consists of movable bars of iron arranged 

 parallel to each other by means of a cross piece. This 

 arrangement facilitates the arrival of the air, and accele- 



The fire-place, rates the combustion. Above the ash-hole is the second 

 opening, which is that of the fire-place, and is carefully 

 closed with a large stone shod with iron, and furnished 

 with two rings, to admit, a hook, by which the door is re- 

 moved whenever fuel is to be thrown in. See Fig. 2- 

 Plate III. 



Chimney, The third aperture is perceptible only by the projecting 



part of the bottom of the chimney, which suggests that 

 the smoke is obliged to surround the interior apparatus : 



The furnace 

 described. 



The ash- hole. 



exactly on a level with the bottom of the thermolamp, 

 which is supported by the interior and anterior part of 



the furnace. 



By 



