FOR GREA T BRITAIN AND IRELAND. 59 



FORCE OF THE WAVES. 



* Smeaton, when speaking of the objection that might 

 be raised against the use of joggles in the masonry of the 

 Eddystone Lighthouse, says : ' When we have to do with, 

 and to endeavour to control, those powers of nature that 

 are subject to no calculation, I trust it will be deemed 

 prudent not to omit in such a case anything that can 

 without difficulty be applied, and that would be likely 

 to add to the security.' This statement of our greatest 

 marine engineer indicates the propriety of carefully 

 collecting any facts that may help us to a more accurate 

 estimation of those forces which he regarded as being 

 ' subject to no calculation.' We shall therefore state a 

 few facts which have been recorded of the destructive 

 power of the waves in inland lakes and in the open ocean." 



" At Port Sonachan, in Loch Awe, where the fetch is 

 under 14 miles of fresh water, a stone weighing a quarter 

 of a ton was torn out of the masonry of the landing slip 

 and overturned." 



" Mr. D. Stevenson, in his * Engineering of North America,' 

 describes the harbours in Lake Erie as reminding him 

 of those on our sea-girt shores, and mentions having seen 

 at the harbour of Buffalo one stone, weighing upwards of 

 half a ton, which had been torn out of its bed, moved 

 several feet, and turned upside down." 



"At the Bishop Rock Lighthouse a bell was broken 

 from its attachments at the level of 100 ft. above the 

 high water-mark during a gale in the winter of 1860 

 (Nautical Magazine, vol. xxi. p. 262) ; and at Unst a door 

 was broken open at a height of 195 ft. above the sea. 

 To these facts may be added, that I know, from the 

 testimony of an eye-witness, of a block of 50 tons weight 

 being moved by the sea at Barrahead, one of the Hebrides." 



