292 



INDEX. 



Design of ground-plans of harbours, 



152-160, 169 

 Destructive effect of falling water, 80- 



82, 178 

 Diagrams, strength of Portland cement, 



129 



, tidal, 53, 51 



, wind, 2, 3 



, wind velocities and pressures, 11 



Difficulties attending the execution of 



work near low water, 259-261 

 connected with rock foundations, 



261-265 

 " Dip " and " strike " of strata should 



be utilized in quarrying, 92 

 Diving, 255 



Dogger Bank, waves break upon, 28 

 Double tides, 53, 54 

 Douglass, Sir J. N., on the mooring of 



light-vessels, 234, 235 



, , on wave-power, 85, 86 



Dover, Admiralty Pier, cost and other 



particulars, 219 



, current past end of, 71 



Straits, tidal current through, 69 



Dove-tailed bond, 281, 282 

 Dowels. See Joggles 

 Dredging generally necessary at har- 

 bour entrances, 153, 285 



, rock, 154 



Drift, littoral, chiefly due to wave- 

 action, 71 



, , influenced by wind, 1, 20 



Drifting sand, methods of arresting, 20- 



22 



Drills for rock-boring, 99, 100 

 Dry bedding of blocks objectionable, 



181, 182, 244, 278 



Duff on value of herring fisheries, 170 

 Dunraven, Lord, on height of waves, 35 

 Dynamite, useful in preparing rock 



foundations, 262 

 , in quarrying, 101 



E 



Earthquakes, waves caused by, 33 

 Earth's crust, movement of, 76-78 

 Electricity, firing charges by, 103 

 Elm, American rock, 137 

 Entrances of harbours, 153-164, 168 



, direction of, 155, 159, 167 



, forms of, 156, 157, 159 



Entrances of harbours, position of, 153, 

 154, 162-164 



, , tidal or " barred," incon- 

 venient and dangerous, 168 



, , width of, 159-161 



Equinoctial tides, 49 



Erosion caused by loose joggles, 280 



of rocks, 105-109 



Establishment, tidal, 55 



Estuary harbours, 150-154 



Evaporation from surface of ocean, 65 



, ocean currents affected by, 65, 66 



Experiments on waves, 23, 24 



Explosives used in quarrying, 101 



Exposure affected by scour during gales, 

 75 



, effective, 73 



, general remarks on, 88 



, how to estimate, 37, 73-75 



, mud as an indication of, 86 



Falling water, effect of, on roadways of 



breakwaters, 80-82, 178 

 Fetch alone no indication of exposure, 73 



, definition of, 73 



, effective length of, limited by 



extent of storms, 73 

 Firing charges in quarrying, 103, 104 

 Fish deteriorate when boats are delayed, 



168 

 Fishery harbours, 165-171 



, berthage, 169 



, difficulty of designing, 165 



9 effect of " range" in, 165-167 



, quay space, 169 

 , vertical type of breakwater 



suitable for, 167 

 , water area required for give 



number of boats, 169 

 Fishing boats and gear, value of, 171 

 Floating breakwaters, 231-235 

 , impossibility of mooring, 232, 



234 



Forced waves, 33 

 Forecasting weather, 6, 14, 19 

 Foreshores, advance of, 285 

 Forth bridge, wind-gauges at, 9 

 Foundations, 257-274 



, bag-work, 181, 188-193, 261 



, benching rock, 262, 263, 265 



, mass-work, 262-264, 266-268 



