On the Origin and Discovoij nj Iron. 165 



As soon as certainty of operation was established, other im- 

 provements would follow in the art of iron-making. As tlie 

 properties of the metal were developed, demand would confer 

 an additional value upon the product. The smith, to use a 

 phrase common to this and other countries, would, in propor- 

 tion as his manufacture increased in value, direct his attention 

 to the " oeconomy of the process." In his first assays, both 

 quantity and proportion would most likely be entirely over- 

 looked, and the real quantity of metal in an ore computed only 

 by the crude and imperfect extracts. Habit and observation 

 would in time point out the utility of having a measure of bulk 

 whereby to repeat those proportions correctly, that experience 

 had taught him were productive of the most luiiform results. 

 A favourable combination of circiunstances in the furnace, 

 might at a fortunate conjuncture enlarge his bloom of iron : 

 this repeated, would lead to a sus2:)icion that more iron might 

 be extracted from the ore, were the manipulation itself more 

 perfect. This would furnish new motives for observation and 

 contrivance. Improvement would follow, and the smith would 

 feel the importance of the result, whether it was equal to one- 

 fourth, one-third or one-half the weight of the ore. It would 

 also be discovered that some ores, however perfectly operated 

 upon, would not jdeld an equal quantity of iron with others : 

 hence would arise the important distinction of rich and lean 

 ores. This simple fact would give a new impulse to exertion. 

 Rich ores would be sought after with avidity, and paid for in 

 proportion to the quantity of metal obtained from them by the 

 smith. When these ceased to exist in plenty upon the surface 

 of the earth, digging woxdd be resorted to ; the art necessary 

 to distinguish between a lean and a rich ore, and the skill ne- 

 cessary to follow them through soil and rock, would become 

 important qualifications. A new class of labourers endowed 

 with superior skill and intelligence would in time be formed, 

 to which has since been given the name of miners. Though 

 we cannot precisely say what was the peculiar form of the iron 

 furnaces or air bloomeries of the Greeks and Romans, yet we 

 may form some idea from what is now practised by other na- 

 tions in the infancy of the art. Park, I tliink, in his Travels 

 in the Interior of Africa, has given a drawing of a low conical 

 furnace, whicii seems an easy and natural structure for a rude 

 age. Small oj)enings at the lower end of the cone to admit 

 tijc air, and a larger orifice at the toji, would, with charcoal, 

 be sulHcient to give a considerable degree of heat. The fur- 

 nace would in tlie first instance be filled with layers of char- 

 coal and iron ore alternately, and the fire ajiplied to the open- 

 ings in the lower extremity of the furnace. The measure of 



heat 



