STUFFY ROOMS 391 



amount of the gas made no sensible difference to them, but increased 

 their pulmonary ventilation. In every one of the experiments they 

 suffered from the heat, and the putting on of the fans gave great relief, 

 and in particular diminished the pulse rate during and after the work- 

 ing periods. The relief became much greater when cold water was 

 circulated through the radiator and the temperature of the chamber 

 lowered 10° F. The subjects wore only a vest, pants and shoes in 

 most of these experiments. When they wore their ordinary clothing 

 the effect on the frequency of the pulse was more marked and the dis- 

 comfort from heat and moisture much greater. 



I have made observations on men dressed in the Fleuss rescue 

 apparatus for use in mines, and exposed in a chamber to 120° F. dry 

 bulb and 95° F. wet bulb. The skin temperature rises to the rectal 

 temperature and the pulse is greatly accelerated — e. g., to 150 — and 

 there arises danger of heat stroke. The conditions are greatly relieved 

 by interposing on the inspiratory tube of the apparatus a cooler filled 

 with carbonic-acid snow. The cool inspired air lowers the frequency 

 of the heart and makes it possible for the men to do some work at 

 95° F. wet bulb, and to endure this temperature for two hours. 



The observations made by Pembrey and Collis on the weaving-mill 

 operatives at Darwen show that the skin of the face may be 4° to 

 13° F. higher in the mill when the wet bulb is 71° F. than at home 

 when the wet-bulb temperature is about 55° F. The tendency of the 

 warm, humid atmosphere of the mill is to establish a more uniform 

 temperature of the body as a whole (surface and deep temperatures) 

 and to throw a tax upon the power of accommodation as indicated by 

 the rapid pulse and low blood-pressure. 



The mill-workers are wet with the steam blown into the sheds, 

 their clothes and bodies are moist, and the long hours of exposure to 

 such uncomfortable conditions are most deleterious to physical vigor 

 and happiness. The operatives asked that they might be allowed to 

 work without steam-injectors and with diminished ventilation, so that 

 the mill rooms became saturated with moisture evaporated from the 

 bodies of the operatives. The old regulations, while forbidding more 

 than 6 parts in 10,000 C0 2 , put no limit to the wet-bulb temperature, 

 and this often became excessive on hot summer days. The operatives 

 were quite right. Less ventilation and a lower wet bulb is far better 

 than ample ventilation and a high wet bulb. The permissible limit 

 of C0 2 has now been raised to 11 parts in 10,000, and the wet-bulb 

 temperature is to be controlled within reasonable limits. 



The efficiency of workers in mills, mines, tunnels, stoke-holes, etc., 

 is vastly increased by the provision of a sufficient draught of cool and 

 relatively dry air, so as to prevent over-taxing of the heat-regulating 

 mechanism. Mr. F. Green informs me that by means of forced 



