54 Dr Davy's Voyage from England to Barhadoes. 



These observations give^ a fair average early morning tem- 

 perature of 98-33, whilst in England it was 98*74 ; and an 

 average night temperature of 97*92, whilst in England it was 

 97-92. ' 



Should more extended observations confirm these conclu- 

 sions, the differences of temperature, at different times of the 

 day, in the two climates, may perhaps be connected with the 

 manner of sleeping in a tropical country, merely covered with 

 a sheet, and commonly in a current of air ; -and in part to the 

 moist state of the skin, presenting a constantly evaporating 

 surface of large extent, especially when wet or moist with 

 perspiration ; and partly to the subsidence of functional ac- 

 tion in sleep, after undue excitement whilst waking. By day, 

 in all the instances mentioned, the temperature had risen to 

 99°, or above that. However, it may be explained, should 

 the fact be established, that the temperature of the body falls 

 in sleep far more in a tropical than in a temperate climate, in 

 a hot than a cool one, it should be suggestive of precautions in 

 sleeping, especially as to too free exposure to the wind or cur- 

 rents of air, and very thin or no bed-clothing — precautions 

 commonly observed by the natives of hot climates, and too 

 <;ommonly neglected by inexperienced strangers unaccustomed 

 to tropical heats ; and very often, I believe, with bad effect, 

 especially when malaria is rife, and exposure to the night air 

 is especially dangerous. 



6. Of the effect of a High Artificial Temperature on Man. 



I availed myself of the opportunity which the steamer offered 

 to notice the effect of a comparatively high temperature on 

 men exposed to it for a considerable time. On the 4th of 

 July, about 11 A.M., when the temperature of the air on deck 

 was 80°, I descended with the principal engineer to the hottest 

 place in the ship, where the men work who are employed about 

 the engines. It was aft, over the boilers ; its floor the plate ; 

 ventilated by one port-hole only, and a small circular opening 

 in the deck, little larger than sufficed to allow a nian to enter. 

 The temperature of the air in it was 111°, and I was told it 

 was often higher. The floor was hotter, disagreeably so to the 

 feet, even protected with boots witk soles of moderate thick- 



