THE AIR OF STOVE-HEATED ROOM8. 333 



will not, I hope, be misunderstood either by the readers of 

 " Knowledge" or by Dr. Siemens himself. 



I may further add that I am animated by a deadly hatred 

 of our barbarous practice of wasting precious coal by burn- 

 ing it in iron fire-baskets half buried in holes within brick 

 walls, and under shafts that carry 80 or 90 per cent of its 

 heat to the clouds; that pollute the atmosphere of our 

 towns, and make all their architecture hideous; that ren- 

 der scientific and efficient ventilation of our houses impos- 

 sible; that promote rheumatism, neuralgia, chilblains, 

 pulmonary diseases, bronchitis, and all the other "ills that 

 flesh is heir to" when roasted on one side and cold-blasted 

 on the other; that I am so rabid on this subject, that if 

 Dr. Siemens, Sir F. Bramwell, and all others who defend 

 this English abomination, were giant windmills in full ro- 

 tation, I would emulate the valor of my chivalric predeces- 

 sor, whatever might be the personal consequences. 



Dr. Siemens stated that the open fireplace " communi- 

 cates absolutely no heat to the air of the room, because air, 

 being a perfectly transparent medium, the rays of heat 

 pass clean through it." 



Here is an initial mistake. It is true that air which has 

 been artificially deprived of all its aqueous vapor is thus 

 completely permeable by heat rays, but such is far from 

 being the case with the water it contains. This absorbs a 

 notable amount even of bright solar rays, and a far greater 

 proportion of the heat rays from a comparatively obscure 

 source, such as the red-hot coals and flame of a common 

 fire. Tyndall has proved that 8 to 10 per cent of all the 

 heat radiating from such a source as a common fire is ab- 

 sorbed in passing through only 5 feet of air in its ordinary 

 condition, the variation depending upon its degree of satu- 

 ration with aqueous vapor. 



Starting with the erroneous assumption that the rays of 

 heat pass " clean through" the air of the room, Dr. Siemens 

 went on to say that the open fireplace " gives heat only by 

 heating the walls, ceiling, and furniture, and here is the 

 great advantage of the open fire;" and, further, that "if 

 the air in the room were hotter than the walls, condensation 

 would take place on them, and mildew and fermentation of 



