Obfervations on Iron and Steel. 55 



Explanation of the Plate. 



Fig. 1 is a plan of the furnace, and fig. 2 is a feclion of it 

 taken at the line AB. The plan is taken at the line CD. 

 The fame parts of the furnace are marked with the fame let- 

 ters in the plan and in the feclion. EE are the pots or 

 troughs into which the bars of iron are laid to be converted. 

 F is the fire-place; P the fire-bars; and R the afti-pit. 

 GG, &c. are the flues. HH is an arch, the infide of the 

 bottom of which correfponds with the line IIII, fig. 1, and 

 the top of it is made in the form of a dome, having a hole 

 in the centre at K, fig. 2. LL, &c. are fix chimneys. MM 

 is a dome fimilar to that of aglafs-houfe, covering the whole. 

 At N there is an arched opening, at which the materials are 

 taken in and out of the furnace, and which is clofely built 

 up when the furnace is charged. At 00 there are holes in 

 each pot, through which the ends of three or four of the bars 

 are made to project: quite out of the furnace. Thefe are for 

 the purpofe of being drawn out occafionally to fee if the iron, 

 be fufficiently converted. 



The pots are made of fire-tiles or fire-ftone. The bot- 

 toms of them are made of two courfes, each courfe being 

 about the thicknefs of the fingle courfe which forms the out- 

 fides of the pots. The infides of the pots are of one courfe, 

 about double the thicknefs of the outfide. The partitions of 

 the flues are made of fire-brick, which are of different thick- 

 neffes, as reprefented in the plan, and by dotted lines in the 

 bottom of the pots. Thefe are for fupporting the fides and 

 bottoms of the pots, and for directing the flame equally- 

 round them. The great object is to communicate to the 

 whole an equal degree of heat in every part. The fuel is put 

 in at each end of the fire-place, and the fire is made the 

 whole length of the pots, and kept up as equally as poffible. 



E 4 XII. Account 



