342 Mr. T. Pridgin Teale [Feb. 5, 



high temperature, and that high temj^erature of fuel does not pro- 

 duce combustion until oxygen is introduced, — therefore we can have 

 a high temperature of fuel, without rapid combustion, provided we 

 control and limit the supply of oxygen. If we have thoroughly 

 grasped these elementary facts, we shall be in a position to under- 

 stand the points to be aimed at in the construction of a fireplace. 



My attention was first directed to the question of waste of fuel 

 at the time of the coal famine some twelve years ago. I read in the 

 * Times,' and acted upon the suggestion, made, I believe, by the late 

 Mr. Mechi, to economise coal by inserting an iron plate on the grid 

 under the fuel so as to cut off all draught through the fire. This 

 undoubtedly induced slow combustion, and economised fuel, but the 

 fire was dull, cold, and ineffective. The plan w^as abandoned. It 

 taught me, however, the fact that combustion could be controlled by 

 cutting off the underdraught, but I did not then see why combustion 

 was spoiled. The reason was that the under surface of the fire was 

 chilled, and the fuel lost its incandescence owing to the rapid loss of 

 heat through the iron towards the open hearth chamber. To some 

 persons even now " Slow combustion stoves " are an abomination, 

 and are supposed to be synonymous with bad combustion. 



The next stage in my firejjlace education was the adoption of 

 the Abbotsford grate. I thereby learnt that the reason why an 

 Abbotsford grate was an advance upon the iron plate lay in the fact 

 that the solid firebrick bottom stored up heat and enabled the fuel 

 to burn more brightly resting upon a hot surface — not upon a 

 cooling iron plate. But Abbotsford grates, and the other class of 

 grates w^ith solid firebrick bottoms, the Parson's grates, have dis- 

 advantages. They are apt to become dull and untidy towards the 

 end of the day, and do not burn satisfactorily with inferior coal. 

 There is a better thing than a solid firebrick bottom, and that is the 

 chamber under the fire closed in front by an " Economiser." 



The history of the next, the most important stage of my fireplace 

 education, was as follows : — 



Some five years ago I made, somewhat accidentally, the discovery 

 that the burning of coal in an ordinary fireplace could be controlled 

 and retarded by the adoption of a very simjjle and inexpensive 

 contrivance, applicable to nearly every existing grate, and that this 

 result could be attained without impairment of, and often with 

 increase of, the heating power of the fire. This contrivance, which 

 I have named an " Economiser," was simply a shield of iron, standing 

 on the hearth, and rising as high as the level of the grid at the 

 bottom of the grate, converting the hearth space under the fire into a 

 chamber closed by a movable door. 



The effect was twofold. The stream of air, which usually rushes 

 through the bottom of the fire, and causes for a short time rapid 

 combustion at a white heat, was thereby cut off, and the air under the 

 fire was kept stagnant, the heated coal being dependent for its com- 

 bustion on the air jmssing over the front and the ii^per surface. The 



