introduced at the Clyde Iron Works, near Glasgow ; and at 

 the fourth meeting of the British Association, held at Edin- 

 burgh in 1834, Dr. Clark gave an account of its success as 

 follows : — 



" That in their previous operations with cold air, 8 tons 

 " 1 cwt. 1 qr. of splint coal (made into coke, at a loss in 



weight of fifty-five per cent.), was required to make 1 ton 

 " of iron. 



" With the use of air heated to about 300° Fahrenheit, 

 " 5 tons 3 cwt. 1 quarter of coal (in coke) produced a ton of 

 " iron, in addition to which, 8 cwt. of coals were used for 

 " heating the air. 



" In 1833, the temperature of the air used being 600^ 

 " Fahrenheit, it was found that raw coal (not coked) might 

 " be used, which circumstance further reduced the quantity 

 " of coal required in the furnace to 2 tons 5 cwt. 1 qr. per 

 " ton of iron made." 



Not having been present at Edinburgh, on the Associa- 

 tion's meeting the following year in Dublin, I stated that 

 the case had not been correctly represented to Dr. Clark,* 



* A similar misrepresentation has also been made to Mr. Mushet, by reason of 

 which he has been led into an error so far as to state, in his most valuable work 

 on iron and steel, pages 922-923, that the materials used at the Milton Works in 

 December, 1834, with cold blast, were for each ton of iron made, — 



Tons. Cwts. Lhs. 



Coals 6 3 2 



Ironstone 4 1 0 



Limestone 0 13 0 



At the same works, in December 1836, with hot blast, — 



Tons. Cwts. Qrs. Lbs. 



Coals per ton of iron in the furnace 2 4 3 14 



Ironstone 3 11 2 21 



Iron Ore 0 0 1 0 



Limestone .7 0 16 0 14 



It is, however, well known, that on an average of the year through, previous to 

 April 1829, when cold blast was used at the Milton Works, the materials con- 

 sumed were — 



Tons. dots. Qrs. Lbs. 



Coals in the furnace 4 18 0 0) per ton 



Ironstone ditto 3 14 3 9>of Iron 



Limestone ditto , 0 14 3 23) made. 



B 2 



