314 REPORT— 1903. 



recorded swells corresponds to a wave velocity about equal to that of the 

 greatest recorded hourly velocity of wind (the velocity of the dominant 

 wave in storms being mucli lower). 



It may be added that no records of swells have been met with having 

 periods approaching those appropriate to a deep-sea velocity equal to that 

 attained during the gusts of a storm. 



Mathematical investigations have pointed to the tendency of wind 

 finally to produce steep waves of velocity equal, or almost equal, to that 

 of the wind. When, however, we come to compare the observed velocities 

 of wind, the observed dimensions of cyclonic storms, and the lengths of 

 waves of velocity equal, or nearly equal, to that of the strongest winds, 

 we find that we rapidly approach a condition of things when the stretch 

 of water subject at any one time to such wind is only a small multiple 

 of the wave length ; a condition in which steep waves could not be 

 maintained. 



On Regidar Vndxdations produced in a Road hy the Use of Sledges. 



An investigation on this subject was completed after last year's report 

 had been sent in, but was made the subject of a paper to Section G 

 (Belfast meeting). These undulations have been observed both in snow 

 and in ordinary road material. Those in snow are a familiar feature in 

 Canada and are termed cahots. An illustration is here given of ' cahots' 

 in ordinary road material as observed upon the road to a slate quarry at 

 Coniston, Lanes. (Plate X.). 



The chief result of the investigation may be summarised thus : when 

 the detritus consolidates readily under pressure, undulations arise spon- 

 taneously by the action of a steadily moving sledge when furrowing a 

 homogeneous road. The wedge of detritus travelling in front of the prow 

 of the sledge becomes compacted, the sledge surmounts it (rolling like a 

 wheel), and the detritus remains behind as an excrescence incorporated 

 with the road. At the same time the sledge pitches, furrowing the road 

 more deeply and accumulating detritus in front, which it finally surmounts 

 with the rolling movement which assists to compress and bind the material, 

 building up the next crest. 



Wave Phenomena of the Niagara. 



I have visited Niagara Falls, N.Y., with a view to reporting upon 

 some of the characters of the waves of rivers which I judged would be 

 seen in full development in the Rapids below the Falls. Three weeks' 

 work showed that the choice of locality for this study was a good one, 

 and afforded opportunity also for the study of phenomena of a kindred 

 character in the falls themselves and in the whirlpool. Indeed, it is to 

 the periodic and pulsative movements that much of the distinctive 

 character and interest of the Falls and Rapids are due. 



There has not yet been sufficient time to work up the results of these 

 observations for publication. 



As an indication of the character of the phenomena observed at 

 Niagara it may, however, be stated that in the tremendous current of the 

 Whirlpool Rapids (depth about 50 feet) there is, in addition to the usual 

 stationary waves of rivers, a remarkable development of visible travelling 

 waves, giving rise to many complex and beautiful results and contributing 



