140 



" In the blast-hearth process a good deal of turf may be 

 used in conjunction with coal, and this is a very great advan- 

 tage in bog districts. The black turf of Ireland is capable of 

 affording an intense heat, and may yet contribute to prove 

 that our natural advantages are not of less account than 

 those of other countries. The quantity of coal consumed in 

 the blast-hearth is by much less than what is required for the 

 reverberatory, and this is one of the chief recommendations of 

 the former. Another is the very small comparative cost at 

 which a compact smelting establishment may be constructed 

 on the blast-hearth principle, and which, nevertheless, will be 

 capable of doing a great deal of work. The long horizontal 

 flue may be dispensed with ; some lead in consequence will be 

 lost, but no small outlay will be saved. Much space is also 

 saved by the blast-hearth. There is a great advantage in 

 smelting on the spot where the ore is raised : expense may, in 

 certain localities, be saved, which would otherwise be incurred 

 by the transport of the ore to one of the great smelting esta- 

 blishments. The mine proprietor will thus have a twofold 

 source of profit. It is not possible to come to any positive 

 conclusions on the comparative advantages of the two furnaces 

 without taking into account local circumstances ; it were an 

 attempt to compare things that are not comparable. There 

 is a trite saying amongst smelters that ' the blast-hearth saves 

 coal and wastes lead ;' and although this is true, yet, as 

 Bishop Watson observes, ' a great quantity of metal, ex- 

 tracted at a great expense, may not produce so much clear 

 profit as a less quantity procured at an easier rate : there is a 

 beneficial limit between the quantity to be obtained and the 

 expense attending the operation, which nothing but expe- 

 rience can ascertain.' 



" On an occasion when it was necessary for me to come to 

 a conclusion on the subject of this comparison, I made expe- 

 riments intended to ascertain the quantity of lead producible 

 from a given weight of ore, and also the cost of its production. 

 The experiments were made with every precaution I could 



