1872.] 



' Shearwater ' Scientific Researches. 



537 



very distinct division between the upper warm and the lower cold stratum, 

 in that portion of the Eastern Atlantic. 



II. To ascertain whether any evidence would be furnished, by the relative 

 Specific Gravities of the surface- and fo^om-waters on the Atlantic slope of 

 the "marine watershed" between Capes Spartel and Trafalgar, of the 

 passage of Mediterranean water over that ridge. 



III. To make a further Dredging-exploration of the comparatively shallow 

 area between Sicily and the Coast of Africa, — part of it constituting the 

 Skerki and Adventure Banks, — from which several specimens were obtained 

 last year that proved of great interest. 



IV. To make a sufficient number of deep Soundings in the Eastern Basin 

 of the Mediterranean, to ascertain whether its water corresponds in Tem- 

 perature and Density with that of the Western basin ; and also, whether 

 the deposit on its bottom is of the same character, and whether the water 

 immediately above it is copiously charged, as in the Western basin, with 

 very finely divided particles in suspension. 



V. To ascertain, by analysis of the Gases of this bottom-water, whether 

 the proportions of Oxygen, Nitrogen, and Carbonic acid correspond 

 with those which had been found in the Northern Atlantic to be compatible 

 with the presence of an abundant Fauna ; or whether, as I suggested in my 

 last year's Report (§ 103), the stagnation of the deeper part of the Medi- 

 terranean basin (in consequence of the want of Thermal Circulation) is 

 attended with such an excess of Carbonic Acid and diminution of Oxygen, 

 as is incompatible with the existence of Animal Life. 



VI. To carry a series of Dredgings along the Northern Coast of Africa, 

 eastward from Malta, in moderate depths, to ascertain how far its Fauna 

 presents the same characters, and the same limitation to depths of between 

 150 and 200 fathoms, that it does in the corresponding part of the Western 

 Basin. 



With the view of enabling me to obtain the requisite assistance in carry- 

 ing out the Zoological portion of the inquiry, and of meeting other scien- 

 tific expenses, the Council of the Royal Society assigned a sum of <£100 

 from the Government Grant ; and this enabled me to secure, as on former 

 occasions, the services of Mr. Laughrin as Dredger and Sifter. — A further 

 sum of £50 was assigned to me from the Donation Fund, as a provision for 

 the expenses of our return from Alexandria, the point at which we were to 

 quit the ' Shearwater.' 



The Admiralty having charged itself, as on former occasions, with the 

 provision of Thermometers and Water-bottles, it was only requisite for me 

 to provide the Apparatus needed for Gas- Analysis and for the accurate de- 

 termination of Specific Gravities. As this last point was of special im- 

 portance, and as I had found the use of a delicate Hydrometer on board 

 ship, when there was even a trifling roll, to be attended with uncertainty, 

 I thought it worth while to make trial of the method of taking Specific 



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