364 



Part III. — Fifteenth Annual Report 



and E.S.E. on the Scotch coast ; on the English coast they were mainly 

 easterly from the 8th to the 11th. From the 12th to the 25th, a 

 northerly element conies in, the wind blowing usually from the N., 

 N.E., and N.N.E., and rising to gales. The effective wind at all the 

 stations in January was from the east and north, the mean direction 

 being E.N.E. E. 



The prevailing winds therefore seem to account for the reversal of 

 the current in December and January, the south and south-east winds 

 driving the water directly northwards parallel to the coast, and the 

 east and north-east winds keeping it up on the east coast of England, 

 whence, as it cannot escape to the south, it passes northwards. None of 

 the drifters were found south of Norfolk, although the strong winds from 

 E.N.E. in January would tend to drive part of the surface water towards 

 the Channel. 



The direct influence of continuous winds, blowing strongly in a uniform 

 direction for a period, in driving the surface water before it, is shown in 

 a number of other cases, as, for example, in November 1894. During 

 almost the whole of that month the wind blew between west and south, 

 and principally from S.W. on the east coast of Scotland (see Table I. p. 

 358 and figs. 1, 2, 3 on PI. XI.), and drifters put in at the beginning of 

 the month 8 and 10 miles off the coast of Aberdeen, were found in 

 December on the west coast of Norway, near Bergen, and to the north 

 of it; the first found had travelled 270 miles in 29 days. These 

 drifters, and the surface water, were, no doubt, blown in a north-westerly 

 direction from the Scottish coast, until they entered the strong northerly 

 drift racing up off the west coast of Norway. 



There are two points upon which something must be said : — (1) The 

 rate of the current ; (2) the depth to which the movement described 

 extends. 



5. The Kate and Depth of the Current. 



With respect to the rate of movement, the same observations that 

 apply to the direction deduced from a few experiments apply also here. 

 It would be wrong to infer the rate from isolated cases, where the 

 drifters may have lain on the beach for some time before being discovered. 

 But this source of error is greatly diminished by repeated instances, and 

 by — what was a very common occurrence — a large proportion of one lot 

 being found on the same day, or on dates close together. In some cases, 

 too, the drifters were picked up by fishing-boats while they were afloat. 



Beginning at the north, with the drifters put away by H.M.S. 

 ' Research ' to the north and west of the Shetlands, we find that those 

 set adrift on 5th August in lat. 60° 38 J' N. long. 5° 35J' W. moved 

 in an easterly direction to the Shetlands, distances ranging from 116 to 

 147 miles in 22 to 26 days, or at a rate of about 5 miles a day. The 

 prevailing winds during the period of flotation were from the north-west 

 and north at North Unst, Fair Isle, and Wick. Those set adrift on 

 30th July to the north of the Shetlands (lat. 61° 49J' N. long. 0° 43' W.) 

 were found about 90 miles to the south in 44 and 46 days, but during 

 the latter part of the period, the winds were blowing strongly from an 

 easterly direction, sometimes veering towards north and sometimes towards 

 south. Those set adrift on 6th August (lat. 60° 2' N. long. 7° 4' W.) 

 and found in Norway travelled about 500 miles in 116 days, or at a 

 rate of between 4 and 5 miles a day. Some put in at Suleskerry, to the 

 west of the Orkneys, travelled eastwards to the Orkneys at a rate rather 

 over 5 miles a day. 



In the Moray Firth the drifters put away at Smith Bank were carried 



