FEDERAL COAL COMPANY. 229 



If a beehive oven is not properly attended to, a 

 large amount of coke may be consumed that 

 might otherwise be saved with reasonable care and 

 attention. The burnt coke deposits ash on the re- 

 mainder, which retards the transmission of heat from 

 the hottest portion of the oven, just above the coke, to the 

 unburnt portion, towards the bottom, and, when watered, the 

 ash is washed down, thus increasing the total of the ash in 

 the coke below. Pretty feathery and stalactitic forms are 

 often seen, especially at the top of a charge; these are due 

 to carbon that has been deposited in the coke from the decom- 

 position of the gases distilled from the coal lower down. 

 To obtain a good yield of coke, the charging and 

 drawing should be done regularly, the coal properly 

 levelled down, and the coke watered to the best advantage. 

 Skill and care are required in controlling the admission or ex- 

 clusion of air to the oven, so as to secure a satisfactory degree 

 of heat at the right time, and as nearly as possible to secure 

 this heat from the gases which are driven oft' during the process 

 of coking, and which would otherwise be entirely wasted. 

 Full control must be had over the air holes and small leaks 

 which might admit air when not wanted. It is not necessary to 

 have a large amount of air to burn out an oven ; every cubic 

 foot of unnecessary air going into an oven causes a loss. An in- 

 crease of air does not necessarily mean increased temperature. 

 At first an excess of air may cool an oven before the gases, 

 which add to the heat by their combustion, are given off. For 

 the first few hours more gases may be given off than the ordin- 

 ary air holes can supply with air for perfect combustion, and the 

 products of combustion may have a difficulty in escaping. 

 Later on matters are reversed, and there would be an excess of 

 air if it were not regulated, and as this tends to cool the 

 charge, one may have to burn some coke to obtain sufficient 

 heat to finish the operation. After drawing a charge, the 

 doors are lowered again and luted, in order to keep the oven 

 warm, so when a fresh charge is dropped in and levelled, the 

 heat stored in the walls is sufficient to start combustion. 



The Mount Kembla Colliery. 



This is the most southern productive colliery in New 

 South Wales. Coal extends further south, but up to the present 

 it has not been proved suitable for mining. This colliery is best 

 known to the public as having been the scene of the greatest 

 colliery disaster in Australia, which took place about 2 p.m. on 

 the 31st July, 1902, whereby 95 men lost their lives, and 14 

 were injured. A monument, erected to the memory of those 

 who were killed, is to be seen in a street of AVollongong, and 

 will remind those in future generations of the dangers attend- 



