230 The Mediterranean Sea 



intermediate depths was much higher than at the first station 

 The mean temperature of the water from the surface to a depth 

 of 200 fathoms was, at the first station 63-75 F., and at the 

 second 66-78 F., or three degrees higher. At the first station 

 all the temperatures down to 100 fathoms are higher than 

 were observed in 1870 in the western basin, but it must be 

 remembered that temperature observations made in different 

 years cannot with justice be closely compared, as the climates 

 of the two years are sure to differ considerably, and in the 

 present case the difference in climate between the summers of 

 1870 and 1871 appears to have been very considerable. 



In the autumn of 1881 a very interesting series of observa- 

 tions were made by Captain Magnaghi, hydrographer of the 

 Italian navy, and Professor Giglioli, on board the Italian 

 surveying ship "Washington," in that part of the western 

 basin which is enclosed between the islands Corsica and 

 Sardinia on the one side and the Italian coasts on the other. 

 It is here that the deepest water of the western basin was found ; 

 and, apart from the great interest attaching to the physical 

 results obtained, the collections made with the dredge in the 

 comparatively lifeless waters were of the very highest import- 

 ance, showing, as they did, a practical identity in the abyssal 

 fauna with that of the open ocean. This is the more remarkable 

 as we have hitherto been accustomed to consider the similarity 

 in the fauna of portions of the ocean remotely distant from 

 each other as being due to the likeness of their temperatures. 

 In the Mediterranean, however, the bottom temperature is 

 quite 20 F. higher than is found in great depths anywhere in 

 the open ocean. 



For determining the temperature of the deep water Captain 

 Magnaghi used the half-turn reversing thermometer of Negretti 

 and Zambra, which in itself is a very beautiful instrument. 

 The mechanical arrangement, however, for reversing, even as 

 improved by Magnaghi, was not so satisfactory, and from 

 certain irregularities in the temperature observations reported 

 the writer is inclined to think that some of the remarkable 

 results obtained, for instance on the nth August, are due to 

 this instrumental imperfection. On that day the water at 



