TRANSACTIONS OF THE SECTIONS. 161 



bottom was only 49°, so that warm water did not extend much beyond one-thii-d 

 of the entire depth. The Gidf-stream at its outset is then not more than 391 miles 

 wide, and 1200 feet deep. 



The velocity has been much exaggerated. From all attainable data the author 

 computes the mean annual rate to be 65'4 miles per day, more in summer, less in 

 winter. As this rate decreases with the depth, the mean velocity of the whole 

 mass does not exceed 49-4 miles per day. As the sectional area of the stream is 

 not more than 6'64 square miles, there are not more than from 294 to 333 cubic 

 miles of water per day passing over a given line in the Gulf of Florida. 



From the entrance of the Gulf to the Narrows, the distance is 330 miles. To the 

 northward of this, it appears as the innermost of a series of warm bands, alternating 

 with cold ones flowing in an opposite direction, and having the cold Ai-ctic cm-rent 

 also flowing southwards, between the stream and the coast. In ten days it arrives 

 oft" Cape Hatteras, with a loss of only 3° of its initial temperature ; in tweiaty days it is 

 ofl" Nantucket, being 14° or 15° cooler still ; it is this rapid course and preservation 

 of its original warmth thus far which has made it so remarkable in all ages, but 

 beyond this it rapidly loses its characteristics. After fifty days it is oS" the banks of 

 Newfoundland, and its warmth is lowered to 51° in summer. In January it is down, 

 to 30°. The distance thus travelled is about 3500 miles ; its velocity is not more 

 than one-third of its commencement, and it has lost all the extra warmth it 

 possessed at the outset ; for the volume of water above 70° in the Narrows will not 

 form a film more than 60 feet thick ofl" Newfoundland. 



The second point insisted on was that it is here more than neutralized, as a ivarm 

 cui-rent, by the ice-bearing Arctic current flowing southwards into its northern 

 edge, bringing a volume of cold water equal fully to one-half the entire stream 

 flowing eastward, and peneti-ating, as a cold-water gulf, shown by the isotherms, 

 from 150 to 200 miles southward of its general limit. It was therefore urged that 

 the Gulf-stream is here so thinned out and cooled down, and further neutralized 

 by the Ai-ctic current, that it could no longer be recognized as a heat-bearing stream, 

 and as such ceased to exist. The southern and warmer portion of the stream 

 passes onwards, also eastward, until it is finally lost on the general drifts about the 

 Azores. 



The third point proposed was, that the warm N.E. stream flowing past the 

 British Isles cannot be taken as the Gulf-stream ; it has a distinct origin, and should 

 have a distinct designation. It is true that there is a continuous stream from 

 the West Indies, past the Banks of Newfoundfand, but not throughout a warm 

 stream ; for the temperature rises considerably, from 20° to 27°, to the eastward 

 of the Banks. How can this be the Gulf-stream ? the warmth must be derived 

 from more southern som'ces. The evidences of this easterly drift (the cocoa-nuts, 

 tropical seeds, &c.") pass onwards to the coast of Norway, to Iceland, &c. It will 

 take a floating body fully 150 days to reach Cornwall from the banks of 

 Newfoundland, and perhaps double that period to reach the North Cape or Ice- 

 land. The area claimed to be influenced by the stream, or raised in its tem- 

 perature, is fully 1,500,000 square miles to the northward of the 50° parallel. 

 The known bulk of the Gulf-stream proper (and it receives no accessions) wiU 

 only give six inches per diem over this area, and this too after an interval varying 

 from one to two years from the time it left the Gulf of Florida. 



The origin of the warm ocean temperatm'e in high latitudes was attributed by 

 the author to the prevalent S.W. winds, which, passing over a higher sea tempe- 

 rature, and also driving the water from that direction, brought to North- Western 

 Europe the climatorial attributes of much more southern regions on the eastern 

 side of the Atlanic, and that this N.E. current, which has only of late years been 

 called the Gulf-stream, should possess a specific term. 



On Trade Routes between Northern India and Central Asia. 

 By T. D. FoKSTTH. 



The author stated that he had devoted his time and energies as a public servant 

 in India in applying geographical knowledge to the purposes of material progTess. 

 In his capacity of practical geographer he "had had occasion to point out an error 



1869. 11 



