146 



to answer : I have known smelting, by the blast-hearth, to a 

 large amount, to be carried on in one of the streets of Dublin. 

 We must also remember that, by smelting on the spot where 

 the ore is raised, much expense is saved in the carriage of ma- 

 terials and produce. And it is a fact that some refractory ores 

 are more easily smelted in the blast-hearth than in the rever- 

 beratory. On the whole, there is little use in endeavouring 

 to come to a determination of the comparative merits of these 

 two furnaces, in the abstract, without reference to the locality. 

 The decision of the question must depend on the circumstances 

 of the place ; sometimes one furnace will be preferable, some- 

 times the other. 



" I can adduce a case in point of the advantageous em- 

 ployment of a blast-hearth at a mine where the reverberatory 

 furnace could not be maintained for want of a sufficient sup- 

 ply of ore, and the only alternative was exportation. When 

 the Glenmalure lead mine (County Wicklow) was in brisk 

 operation some years since, the following were the estimates 

 of smelting on the spot, and exporting it to the nearest mar- 

 ket :— 



£ s. d. 

 Cutting out the ore from the rock, per ton, . . 3 17 6 



Royalty (as it should have been), 1 10 



Dressing, 16 



Smelting, by the blast-hearth, 17 9 



7 1 3 

 '• The produce was 12cwt. 3qrs. 8 lbs. of pig-lead; its 

 carriage to Dublin, 13*. 8d., added, made its cost £7 I4s. lid. 

 in Dublin ; but there it was sold for £9 1 2*. 4d., leaving a 

 profit of £l 17*. 5d. per ton of ore. Had the same ore been 

 exported to Dee-bank, the additional charge of carriage to 

 Wicklow, storage, freight, insurance, two commissions, and 

 an assay, would increase the first cost of the ore to £7 6s. 4d., 

 while the price obtainable at Dee-bank was but £8 175. 6d. ; 



