The Sewerage of Sea Coast Towns

by Henry Charles Adams

Mound 60° C.G. 47° Mill.
[Greek: phi]
Centre of shoal
Mound 55° C.G. 57° 30' Mill.
[Greek: phi]
Centre of shoal.

Project the positions on a scale of 5 in = a mile, giving the centre of the shoal." It should be noted that the sign [Greek: phi] signifies stations in one line or "in transit," and C G indicates coastguard station. The order of lettering in Fig. 44 shows the order of working.

[Illustration: Fig. 44.—Method of Locating Point in Water
When Observations Have to Be Taken Beyond It.]

The base lines A B and A C are set out from the lengths and directions given; then, when the boat at D is "in transit" with the centre of the shoal and the coastguard station, the angle formed at D by lines from that point to B and A is 60°, and the angle formed by lines to A and C is 47°. If angles of 90° - 60° are set up at A and B, their intersection at E will, as has already been explained, give the centre of a circle which will pass through points A, B, and D. Similarly, by setting up angles of 90°-47° at A and C, a circle is found which will pass through A C and D. The intersection of these circles gives the position of the boat D, and it is known that the shoal is situated somewhere in the straight line from D to A. The boat was then moved to G, so as to be "in transit" with the centre of the shoal and the mound, and the angle B G A was found to be 55°, and the angle A G C 57° 30'. By a similar construction to that just described, the intersection of the circles will give the position of G, and as the shoal is situated somewhere in the line G B and also in the line A D, the intersection of these two lines at K will give its exact position.

Aberdeen Sea Outfall
Admiralty, Diving Regulations of
—Charts, Datums for Soundings on
—Main Currents Shown on
Age of Tide
Air Pressure on Tides, Effect of
Almanac, Nautical
Analysis of Cement
—Sea Water
Anchor Bolts for Sea Outfalls
Anemometer for Measuring Wind
Aphelion
Apogee
Atlantic Ocean, Tides in
Autumnal Equinox
Barometric Pressure, Effect on Tides of
Beach Material, Use in Concrete of
Beaufort Scale for Wind
Bench Mark for Tide Gauge
"Bird" Tides
Board of Trade, Approval of Outfall by
Bolts for Sea Outfall Pipes
Box Sextant
Bristol Channel
—Datum for Tides at
Buoy for Marking Position of Outfall
Can Buoy to Mark Position of Outfall
Cast Iron, Resistance to Sea Water of
Cement, Action of Sea Water on
—Analysis of
—Characteristics Causing Hardening of
—Setting of
—Effect of Saline Matters on Strength of
—Sea Water on Setting Time of
—Physical Changes Due to Action of Sea Water on
—Precautions in Marine Use of
—Retardation of Setting Time of
—Tests for Marine Use of
Centrifugal Force, Effect on Tides of
Centripetal Force, Effect on Tides of
—Variations in Intensity of
Charts, Datum for Soundings on
—Main Currents Shown on
Chepstow, Greatest Tide at
Clifton, Tides at
Compass, Magnetic Variation
—Marine
—Prismatic
Concentration of Storm Water in Sewers
Concrete, Action of Sea Water on
—Composition to Withstand Sea Water
—Destruction in Sea Water of
Crown, Foreshore owned by
Currents and Tides. Lack of co-ordination in change of
—Formation of
—in Rivers, 30
—Observations of
—Variation of Surface and Deep
—Variations in Velocity of
Current Observations by Marine Compass
—Theodolites
—Floats for
—Hydrographical Surveying for
—Method of making
—Plotting on Plans, The
—Selecting Stations for
—Special points for consideration in making
—Suitable Boat for
—Trigonometrical Surveying for
Datum Levels for Tides
Declination of Sun and Moon
Decompression after Diving
Density of Sea Water
Derivative Waves
Design of Schemes, Conditions governing
Diffusion of Sewage in Sea
Discharge from Sea Outfalls, Calculations for
—Precautions necessary for
—Time of
Disposal of Sewage by Diffusion
—dependent on time of Discharge
Diurnal Inequality of Tides
Diverting-plate Storm Overflow
Diving
—Illnesses caused by
—Instruction in
—Medical Examination previous to
—Physical Principles involved in
—Equipment
Diving Equipment, Weight of
Dublin, Datum for Tides at
Earth, Distance from Moon
—Sun
—Orbit around Sun of
—Size of
—Time and Speed of Revolution of
Equinox
Erosion of Shore caused by Sea Outfalls
Establishment
Flap Valves on Sea Outfall Pipes
Floats, Deep and Surface
—to govern Pumping Plant
Foreshore owned by Crown
Gauges, Measuring flow over Weirs by
Gauging flow of Sewage
—, Formula: for
Gradient, Effect on Currents of Surface
—Tides of Barometric
Gravity, Specific, of Sea Water
—Tides caused by
Great Crosby Sea Outfall
Harbour and Fisheries Dept., Approval of Outfall by
Harwich, Mean Level of Sea at
High Water Mark of Ordinary Tides
Hook-Gauge, for Measuring flow over Weirs
Hull, Mean Level of Sea at
Hydrographical Surveying Problems in Current Observations
Impermeable Areas, Flow of Rain off
—Percentage of
—per Head of Population
Indian Ocean, Tides in
Infiltration Water
Irish Channel, Analysis of Water in
Iron, Effect of Sea Water on Cast
June, Low Spring: Tides in
Kelvin's Tide Predicting Machine
Land, Area of Globe Occupied by
Leap-weir Storm Overflow
Liverpool, Datum for Tides at
—Soundings on Charts of
—Tide Tables
Lloyd-Davies, Investigations by
Local Government Board, Current Observations Required for
London, Datum for Port of
Low Water Mark of Ordinary Tides
Lunar Month
Lunation
Magnetic Variation of Compass
Marine Compass
Mean High Water
Mersey, Soundings on Charts of
Mixing Action of Sewage and Water
Moon, Declination of
—Distance from Earth of
—Effect on Tides of
—Mass of
—Minor Movements of
—Orbit around Earth of
—Perigee and Apogee
Morse Code for Signalling
Nautical Almanac
Neap Tides
—Average Rise of
Orbit of Earth around Sun
—Moon around Earth
Ordinary Tides, lines on Ordnance Maps of
Ordnance Datum for England
—Ireland, 17
—Records made to fix
—Maps, lines of High and Low Water on
Outfall Sewers, Approval by Board of Trade of
—Calculations for Discharge of
—Construction of
—Detail Designs for
—Details of cast-iron Pipe Joints for
—Flap Valves on end of
—Inspection during Construction of
—Marking position by Buoy of
—Selection of Site for
Overflows for Storm Water
Pacific Ocean, Tides in
Parliament, Current Observations Required for
Perigee
Perihelion
Piling for Sea Outfalls
Pipes, Joints of Cast Iron
—Steel
Plymouth, Mean Sea Level at
Predicting Tides
Primary Waves
Prismatic Compass
Pumping
—Cost of
—Plant
—Management of
—Utilisation of Windmills for
Pumps for Use with Windmills
Quantity of Rainfall to Provide for
—Sewage to Provide for
Rainfall
—at Times of Light Winds
—Frequency of Heavy
—in Sewers
—Intensity of
—Storage Capacity to be Provided for
—To Provide for
Range of Tides
Rise of Tides
Screening Sewage before Discharge
—Storm Water before Overflow
Sea, Mean Level of
Sea Outfalls, Calculations for Discharge of
—Construction of
—Design of
—Lights and Buoy to mark position of
—Selection of Site for
Seashore Material used in Concrete
Sea, Variation around Coast in level of
—Water, Analysis of
—Effect on Cast-Iron of
—Effect on Cement
—Galvanic action in
—Weight of
Secondary Waves
Separate System of Sewerage
Sewage, Effect of Sea Water on
—Gauging flow of
—Calculations for
—Hourly and daily variation in flow of, 42
—Quantity to provide for
Sewers, Economic considerations in provision of Surface Water
—Effect on Design of Scheme of Subsidiary
—Storm Water in
Sextant, Box
Signalling, Flags for
—Morse Code for
Solstice, Summer and Winter
Soundings on Charts, Datum for
Southampton, Tides at
Southern Ocean, High Water in
—Origin of Tides in
—Width and Length of
Specific Gravity of Sea Water
Spring Tides
—Average Rise of
—Variation in Height of
Storage Tanks, Automatic High Water Alarms for
—Determination of Capacity of
—For Windmill Pumps
Storm Water in Sewers
—Overflows
Subsidiary Sewers, Effect on Design of Scheme of
Summer Solstice
Sun, Aphelion and Perihelion
—Declination of
—Distance from Earth
—Effect on Tides of
—Mass of
—Minor Movements of
Surface Water Sewers, Average Cost of
—Economic Considerations in Provision of
Surveying, Problems in Hydrographical
—Trigonometrical
Thames Conservancy Datum
—Flow of Sewage in
Tidal Action in Crust of Earth
—Attraction
—Day, Length of
—Flap Valves on Sea Outfall Pipes
—Observations, Best Time to Make
—Records, Diagram of
—Rivers, Tides and Currents in
—Waves, Length of Primary
—Secondary or Derivative
—Speed of Primary
—Velocity of
Tide Gauge, Method of Erecting
—Selecting Position of
Tide, Observations of Rise and Fall of
Tide-Predicting Machine
—Recording Instrument
—Tables
Tides, Abnormally High
—Age of
Tides and Currents, Lack of Co-ordination in Change of
—Diagrammatic Representation of Principal
—Diurnal Inequality
—Double, 9
—Effect of Barometric Pressure on
—Centripetal and Centrifugal Force
—Storms on,
—Extraordinary High
—Formation of
—in Rivers
—lines on Ordnance Maps of High and Low Water of
—Propagation to Branch Oceans of
—Proportionate Effect of Sun and Moon on
—Range of
—Rate of Rise and Fall of
—Rise of
—Spring and Neap
—Variations in Height of
Towers for Windmills
Trade Wastes, Effect on flow of Sewage of
Trass in Cement for Marine Vork
Trigonometrical Surveying for Cuirent Observations
Trinity High Water Mark
Upland Water, Effect on Rivers of
Valves on Sea Outfall Pipes
Velocity of Currents
Vernal Equinox
Visitors, Quantity of Sewage from
Volume of Sewage
Water, Area of Globe occupied by
—Fittings, Leakage from
—Power for Pumping
—Supply, Quantity per Head for
—Weight of
Waterloo Sea Outfall
Waves, Horizontal Movement of
—Motion of
—Primary and Secondary
—Tidal
—Wind
Weight of Fresh Water
—Sea Water
—Sewage
Weirs for Gauging Sewage, Design of
—Storm Overflow by Parallel
Weymouth, Mean Level of Sea at
Wind
—Beaufort Scale for
Wind, Mean Hourly Velocity of
—Measuring Velocity of
—Monthly Analysis of
—Power of Windmills According to Velocity of
—Rainfall at Time of Light
—Velocity and Pressure of
—Waves
Windmills
—Comparative Cost of
—Details of Construction of
—Effective Duty of
—Efficient Sizes of
—For Pumping Sewage
—Height of Towers for
—Power in Varying Winds of
Winter Solstice

End of Project Gutenberg's The Sewerage of Sea Coast Towns, by Henry C. Adams