278 Scientific Proceedings^ Royal Dublin Society. 



the harbour. There was no "run" in and out of the harbour, as 

 on the 1st February, but there were two contemporaneous opposite 

 currents at different levels, the upper one flowing in under wind 

 pressure, the lower one flowing out. Though the tide was ebbing, 

 the current, in the case of so small a harbour, ascribable to that 

 cause would be comparatively insignificant. 



On Oct. 19th, 1882, Mr. William Brovrae, boatman, of Tor- 

 quay, informed me that he had nearly lost his cutter-yacht 

 " Lapwing " during the southerly breeze of the preceding night, as 

 she had broken from her moorings, and only been recovered by the 

 coastguard as she was going round the New Pier. On pointing 

 out that the yacht must have been going in the teeth of wind and 

 wave, my informant said it was so, and attributed the occurrence to 

 an eddy. As, however, the tidal current at the spot indicated is 

 very feeble, I have no doubt the yacht was under the influence of a 

 strong wind- raised current, working seawards, under the lee of the 

 pier. Mr. W. M. Baynes has favoured me with the following 

 note : — " Jan. 10, 1884. With reference to the undertow in Tor- 

 quay harbour, I remember watching, about two years ago, what 

 appeared to be a ship's boatfuU of water, her gunwales being just 

 awash, slowly travelling frorp. the old pier head across the new har- 

 bour in the teeth of a strong south-easterly wind. I think she 

 fouled two or three moored vessels, and, on being pushed clear, de- 

 terminedly resumed her windward course." 



The above cases illustrate the action of wind-raised currents in 

 a tidal harbour, and in one of the minor inlets of Torbay. Torbay 

 itself affords another instance on a larger scale. This bay may be 

 described as a rectangular inlet, some four and a-half miles wide at 

 the mouth, and about three miles deep from mouth to bight. In 

 the bight of the bay the bottom slopes seawards very gently for 

 about a mile, when a maximum depth of six fathoms at low-water 

 is attained, and this depth remains constant over several square 

 miles in the centre of the bay. Easterly winds blow into the bay, 

 and raise the sea. Those from the westward are smooth-water 

 winds, being off shore. Easterly winds are the only ones that can 

 affect the bottom of the bay by either wave-currents or wind-raised 

 currents.. During the more than eleven years in which I have taken 

 notes bearing on the action of waves and currents on the bottom of 

 Torbay, I have been much perplexed by the apparent inconsistency 



