356 BOOK IX. 



of the bellows. The whole of the front furnace wall is not more than five feet 

 high, so that the ore may be conveniently put into the furnace, together with 

 those things which the master needs for his work of smelting. Both the side 

 walls of the furnace are six feet high, and the back one seven feet, and they 

 are three palms thick. The interior of the furnace is five palms wide, six 

 palms and a digit long, the width being measured by the space which lies 

 between the two side walls, and the length by the space between the front and 

 the back walls ; however, the upper part of the furnace widens out somewhat. 



There are two doors in the second wall if there are six furnaces, one 

 of the doors being between the second and third furnaces and the other 

 between the fourth and fifth furnaces. They are a cubit wide and six feet 

 high, in order that the smelters may not have mishaps in coming and going. 

 It is necessary to have a door to the right of the first furnace, and similarly 

 one to the left of the last, whether the wall is longer or not. The second 

 wall is carried further when the rooms for the cupellation furnaces, or any 

 other building, adjoin the rooms for the blast furnaces, these buildings being 

 only divided by a partition. The smelter, and the ones who attend to the 

 first and the last furnaces, if they wish to look at the bellows or to do anything 

 else, go out through the doors at the end of the wall, and the other people go 

 through the other doors, which are the common ones. The furnaces are placed 

 at a distance of six feet from one another, in order that the smelters and their 

 assistants may more easily sustain the fierceness of the heat. Inasmuch as 

 the interior of each furnace is five palms wide and each is six feet distant 

 from the other, and inasmuch as there is a space of four feet three palms at 

 the right side of the first furnace and as much at the left side of the last 

 furnace, and there are to be six furnaces in one building, then it is necessary 

 to make the second wall fifty-two feet long ; because the total of the widths 

 of all of the furnaces is seven and a half feet, the total of the spaces between 

 the furnaces is thirty feet, the space on the outer sides of the first and last 

 furnaces is nine feet and two palms, and the thickness of the two transverse 

 walls is five feet, which make a total measurement of fifty-two feet.^ 



Outside each furnace hearth there is a small pit full of powder which is 

 compressed by ramming, and in this manner is made the forehearth which 

 receives the metal flowing from the furnaces. Of this I wiU speak later. 



Buried about a cubit under the forehearth and the hearth of the furnace 

 is a transverse water-tank, three feet long, three palms wide and a cubit deep. 

 It is made of stone or brick, with a stone cover, for if it were not covered, the 

 heat would draw the moisture from below and the vapour might be blown 

 into the hearth of the furnace as well as into the forehearth, and would 

 dampen the blast. The moisture would vitiate the blast, and part of the 

 metal would be absorbed and part would be mixed with the slags, and in 

 this manner the melting would be greatly damaged. From each water-tank 

 is built a waUed vent, to the same depth as the tank, but six digits wide ; 



^Agricola has here either forgotten to take into account his three-palm-thick furnace 

 walls, which will make the length of this long wall sixty-one feet, or else he has included this 

 foot and a half in each case in the six-foot distance between the furnaces, so that the actual 

 clear space is only four and a half feet between the furnace with four feet on the ends. 



