172 A JOURNEY FROM MADRAS THROUGH 
CHAPTER forced through the muzzle. The lower part of the bellows Is re- 
tained in its place by a rope fastened to the lower angle (11), and 
June 13 . supported by an elastic piece of timber (13), which is fastened to 
one of the posts of the hut, like a turner’s lathe. The muzzles of 
both the bellows are inserted in one common tube (14), which is 
made of baked clay, and is placed in a sloping direction, so as to 
pass through a mass of moist clay (15), that occupies the front of 
the furnace above the first mentioned stone (3). Above this Is 
placed a large tile (lb); and the empty spaces between this and the 
mound (1) are filled up with moist clay (17). The furnace is now 
cylindrical, and open at top, on which is placed a chimney (18) 
made of baked clay, in the form of two truncated cones joined to- 
gether by the apices. Of these the upper cone is by far the shortest. 
From this it must be observed, that the whole lower front of the 
furnace is moveable ; and when it has been newly built up, a little 
charcoal is burned in it for an hour, to dry the moist clay by which 
the various parts are connected. The rents formed during this ope- 
ration must be carefully closed with more clay, and the furnace is 
then ready for immediate use. 
For smelting the black sand, the following is the process. A 
quantity of the sand is measured out, and divided into three parts, 
each of which I found to weigh a little more than 25 pounds 11 
ounces avoirdupois. Three baskets of charcoal are then set aside, 
of which each contains about a bushel. Two of the baskets of char- 
coal are then put in by the top of the chimney, and above these 
one third part of the sand. The fire is then kindled, and urged with 
the bellows. When the fire subsides, one half of the remaining 
charcoal, and another third of the sand, are put in ; and, when those 
have again subsided, the remainder of the sand and charcoal Is 
added, and the fire is urged six hours and a half from the com- 
mencement. The front of the furnace is then broken, and on re- 
moving the walls a mass of iron is found at the bottom, which is 
taken out with forceps, and cut into two blocks, weighing each half 
