400 Captain Wauchope o?i Sea-Water, 



Along with this notice, I send the result of three other ex- 

 periments* of my own, for ascertaining the temperature of the 

 deep sea water. I send also the result of an experiment of the 

 same kind made by Captain Sabine, who was good enough to 

 favour me with an account of it ; it is hardly to be supposed 

 that no alteration took place in the temperature of the deep 

 water before getting it to the surface : from these experiments, 

 however, I do not think it improbable that, at some given 

 depth, the temperature of the sea may be found at 40° all over 

 the world. 



I inclose also a journal of the thermometer and barometer 

 during a gale of wind off the Cape of Good Hope, with re- 

 marks made at the time, from which one is led to suppose that 

 these gales act in a spiral. The barometer was adjusted with 

 the Royal Society's standard, which is an important desidera- 

 tum, as it is not uncommon to find one marine barometer dif- 

 fering from another more than two-tenths of an inch. It would 

 be very desirable to have the range of the barometer for dif- 

 ferent latitudes, to enable the navigator to know when to ex- 

 pect bad weather. During the heaviest gale off the Cape of 

 Good Hope, I never saw it lower than 29.51 inches ; whereas, 

 on the coast of Great Britain, the mercury may fall half an 

 inch lower, without expectation of bad weather. 



Soundings made to ascertain the Temperature of the Sea at great 

 Depths : 



* For previous experiments, vide vol. iv. p. 161 of Memoirs of Wemerian 

 Natural History Society. 



