29 6 



INDEX. 



Riy Bank, waves break upon, 27 



Roadsteads, 157, 158, 163 



Roadways of breakwaters, effect of fall- 

 ing water upon, 80-82, 207 



Rock, benching, under water, 262, 263, 

 265 



, blasting, 92-94, 101-104 



, boring, 96-100 



, foundations, 257-270 



Rollers arriving before gale, 19 



, direction of, 34, 74 



Roman cement concrete, 122, 123 



, properties and uses of, 122, 



123, 130 



, strength of, 130 



Rubble, danger of, as hearting, 177-179, 



207 



, depths to which disturbed by wave- 

 action, 201, 202 



, founding upon, 273, 274 



, injurious effect of discarding small, 



in constructing Plymouth breakwater, 

 203 



, levelling up rock foundations with, 



270 



, modes of depositing, in mounds, 



202, 240, 241, 244-246 



, settlement of, in mounds, 207, 275- 



278 



, slopes assumed by, in mounds, 



198-200 



, space occupied by, in mounds, 204 



Rubble mounds of breakwaters injuri- 

 ously affect character of waves, 29-31, 

 205 



Russell, Scott, experiments on waves, 

 23, 24 



S 



St. Heliers (Jersey) landing-pier, damage 



to, 178 

 St. Jean de Luz (Artha breakwater), 209, 



210, 215 

 Sand, bags of, useful in foundation work, 



259, 261 



, founding upon, 270, 271 



Sand-blast, 107 

 Sand-drifts, 20 



, methods of arresting, 21, 22 



Sandy coasts, harbours on, 286 

 Sartorius, Admiral Sir Gr. R., on floating 



breakwaters, 233, 234 



Saxicava, 112 



Scoresby on height of waves, 36 



Scott, design for wave-screen, 228 



Scour during gales affects exposure, 75 



Scouring power of currents, 160 



Screens. See Wave-screens 



Scupper-nailing, 134 



Seam -firing in quarries, 101 



" Send " of vessels should be allowed for 

 in determining depth at harbour en- 

 trances, 154 



Setting concrete blocks, 253-255 



Setting-machines, exceptionally large, 

 used at Leixoes, 237 



used at Colombo, Mormugao, and 



Kurrachee, 194, 251 



, various types of, described, 250- 



253 



, weight of, causes settlement in 



work, 181, 276 



Settlement, 180, 181, 275-278, 283 



, caused by weight of " Titans," or 



setting-machines, 181 



, , breakwater super- 

 structures, 275-277 



of Alderney breakwater, 207, 276 



of Colombo breakwater, 181, 277 



of Holy head breakwater, 276 



of horizontally coursed work, 277 



of Manora breakwater, 277, 282 



of Mormugao breakwater, 277 



. of eloping block-work, 276, 282, 



283 



usually greatest in breakwaters of 



mound type, 275 



Shelter, degree of required, affects design 

 and cost of breakwaters, 147, 148 



Shingle, eroding power of, 106, 107 



Silting, 284-288 



causes advance of foreshores, 285 



, process of, 284 



under lee of isolated breakwaters, 



287 



Simoda, waves caused by earthquake at, 

 33 



Slag from iron furnaces, specific gravity 

 of, 113 



used for constructing break- 

 waters, 113 



Sleat Sound, " race " through, 70 



Slipways, 168 



Sloping-block system of construction, 

 advantages of, 181, 194, 197 



