35 2 Limits of our Coal Supply. [July? 



well-known experiments of Blagden, Sir Joseph Banks, and 

 others have shown that the human body can endure for 

 short periods a temperature of 260 F., and upwards. My 

 own experience of furnace-work, and of Turkish baths, 

 quite satisfies me that I could do a fair day's work of six or 

 eight hours in a temperature of 130° F., provided I were 

 free from the encumbrances of clothing, and had access to 

 abundance of tepid water. This in a still atmosphere, but 

 with a moving current of dry air capable of promoting 

 vigorous evaporation from the skin, I suspect that the tem- 

 perature might be ten or fifteen degrees higher. I enjoy 

 ordinary walking exercise in a well-ventilated Turkish bath 

 at 150 , and can endure it at 180°. 



In order to obtain further information on this point, I 

 have written to Mr. Tyndall, the proprietor of the Turkish 

 baths at Newington Butts. He is an architect, who has had 

 considerable experience in the employment of workmen and 

 in the construction of Turkish baths and other hot air 

 chambers. He says : " Shampooers work in my establish- 

 ment from four to five hours at a time in a moist atmosphere 

 at a temperature ranging from 105 to no°. I have myself 

 worked twenty hours out of twenty-four in one day in a tem- 

 perature over no°. Once for one half hour I shampooed in 

 185 . At the enamel works, in Pimlico, belonging to Mr. 

 Mackenzie, men work daily in a heat of over 300 . The 

 moment a man working in a no° heat begins to drink 

 alcohol, his tongue gets parched, and he is obliged to 

 continue drinking while at work, and the brain gets so 

 excited that he cannot do half the amount. I painted 

 my skylights, taking me about four hours, at a temperature 

 of about 145 ; also the hottest room skylights, which took 

 me one hour, coming out at intervals for a cooler, at a tem- 

 perature of 180 . I may add in conclusion, that a man can 

 work well in a moist temperature of no if he perspires 

 freely." 



The following, by a writer whose testimony may be safely 

 accepted, is extracted from an account of ordinary passenger 

 ships of the Red Sea, in the " Illustrated News," of No- 

 vember 9, 1872: "The temperature in the stoke-hole was 

 145 . The floor of this warm region is close to the ship's 

 keel, so it is very far below. There are twelve boilers, six 

 on each side, each with a blazing furnace, which has to be 

 opened at regular intervals to put in new coals, or to 

 be poked up with long iron rods. This is the duty of 

 the poor wretches who are doomed to this work. It is hard 

 to believe that human beings could be got to labour under 



