14 



No air being admitted to the coking spaces, no surface burning 

 of the coke takes place, and, consequently, no loss, as in open 

 forms of oven. 



The coking spaces are vertical, placed side by side, and sur- 

 rounded by flues on both sides. The products of combustion are 

 drawn off through a pipe at the top of the oven, the tar and 

 other valuable matters extracted, and the waste gases brought 

 back to a grate in front of the oven, on which a small lire is 

 kept burning. The waste gases immediately ignite on entering 

 this grate, pass on, and burn in the flues around the coking 

 spaces, passing first to the top of the oven, then in a zigzag 

 course to the bottom, and away through a flue underneath the 

 oven to the chimney. 



The ovens are charged from trucks travelling on rails on top 

 of the ovens, the charging holes being afterwards covered and 

 luted up. 



The whole mass of coke is usually pushed out by means of a 

 ram. 



Only a very small fire is necessary to be kept burning on the 

 grate, it being made up once in 12 hours. 



34. Model of a charcoal annealing furnace. 



E. 134. 1B68. Made bij J. Schroeder, Darmstadt. 



35. Model of a calcining furnace. 



E. 132. 1868. Made by J. Schroeder, Darmstadt. 



36. Metallurgical diagrams showing the construction 

 of different types of furnaces and various methods of pro- 

 duction of steel, iron, and fuel. Set of 22. Size 3 ft. 

 4 in. by 2 ft. 5^ in. Prepared by Professor William H. 

 Greenwood. 



1890. Published by Chapman fy Hall. 



3. METALS AND METALLIC ORES. 



37. Collection formed by the late Dr. Percy, E.R.S., 

 illustrative of his treatise on Metallurgy. 



This collection, w^hich contains some 3,700 specimens, 

 was acquired during the period extending from 1842 to 

 1889, and comprises examples of fuels, ores, metals, and 

 their alloys, also illustrations of processes and of the 

 adaptability of various metals to industrial purposes. 



A full description of each object is contained in a 

 catalogue specially prepared by Prof. J. F. Blake for 



