Page:History of merchant shipping and ancient commerce (Volume 2).djvu/587



BIRKENHEAD BASINS. —-++-++++—  |                      |           |  Height  |            |            | |   | Width of  | of Piers |   Water    |   Lineal   | |                     | Entrance. | above   |   Area. | Quayage. |  |                      |           |  Datum. |           |            |   ++-++++   |                      | Ft. In. | Ft. In. | Acres Yds. | Miles Yds. |  | Low-Water Basin      | 300    0  | 26   0   |   14     0 |   0   1360 | | North Basin         | 500    0  | 31   0   |    4  2843 |   0    689 | |                                            +++   | Total Water Area and Quay Space of the   }  |   18  2843 |   1    269 | |    Birkenhead Basins                    }  |            |            | |  Do. do. do. Docks           |  147   722 |   8    609 | |                                            +++   |                          Total              |  165  3565 |   9    878 |

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=======================================+============+============+==        TOTAL AREA OF THE LIVERPOOL AND BIRKENHEAD DOCKS AND BASINS. —-+-+++—  |                                             | Acres Yds. | Miles Yds. |  | Total Water Area and Quay Space of the   }  |            |            | |    Liverpool Docks and Basins           }  |  259   587 |  18    916 | |                                            |            |            |   | Total Water Area and Quay Space of the   }  |            |            | |    Birkenhead Docks and Basins          }  |  165  3565 |   9    878 | |                                            |            |            |   |                               Total         |  424  4152 | 28      34 |

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=======================================+============+============+==                      LEVELS OF TIDES AT LIVERPOOL.

''Derived from the Record of the Self-Registering Gauge at George's Pier deduced from Ten Years' Observations, 1854 to 1863. Datum Old Dock Sill.'' +-+-                                                     | Ft. In. | An extraordinary High Tide, as marked on the      }  |  25   0     | { Above Leasowe Lighthouse                            }  |             | { Datum. An extraordinary High Tide, 20 January, 1863         |  23   9     |     " Average High-Water Mark of Equinoctial Spring Tides.  |  21   1     |     " Average High Water of Spring Tides, including        |             | Equinoctial Tides                                |  19   0-1/2 |     " Average High-Water Mark of Ordinary Spring Tides,     |             |    excluding the Equinoctial Tides                   |  18  10     |     " Mean High-Water Level                                |  15   6     |     " Highest High-Water Mark of Neap Tides                 |  14   8     |     " Average High-Water Mark of Ordinary Neap Tides       |  11   7     |     " Lowest High-Water Mark of Neap Tides                  |   8   7     |     " Mean Tide Level (Ordnance Datum)                     |   5   0     |     " Highest Low-Water Mark of Neap Tides                  |   4   1     |     " Average Low-Water Mark of Ordinary Neap Tides        |   1   5     | { Below |            | { Datum. Lowest Low-Water Mark of Neap Tides                  |   3  10     |     " Mean Low-Water Level                                  |   5   6-1/2 |     " Average Low-Water Mark of Ordinary Spring Tides,     |             | exclusive of Equinoctial Tides                   |   8   8     |     " Average Low-Water Mark of Spring Tides, inclusive of  |             |    Equinoctial Tides                                 |   8  10     |     " Lowest Low-Water Mark of Equinoctial Spring Tides    |  10   4     |     " +-+-