Henry C. Adams

Capitolo 18

Mersey is reduced to a datum 20 fts under the old windowsill of basin that
it is 125 fts under the level of low water of spring tides and to the agenda.
The datum of every various chart as datum of Artillery of regards, and in the
case of charts that embraces a great area the datum varies along the coast.

The following table gives the autumn during every mezz'ora of the
typical tides shown in Fig tree, 6 (sees page 15) from that it the wish
both considering that the percentage of maximum it happens to on mean-tide, while
very small movement takes first place during the mezz'ora
and the mezz'ora after the turn of the tide:--

Proposes me.

Percentage of fall of tides.

State of Eqionoctial Ordinary Á. the lowest agenda
Tide.             Tides.    Spring tides.  Tides of Neap.  Tides of Neap.

Tall water          --           --           --           --
1/2 hour later 0.44 0.40 0.22 0.19
1 " " 0.96 0.80 0.40 0.31
1-1/2 " " 1.39 1.14 0.68 0.53
2 " " 1.85 1.56 0.72 0.59
2-1/2 " " 1.91 1.64 0.84 0.68
3 " " 1.94 1.66 0.86 0.70
3-1/2 " " 1.94 1.66 0.86 0.70
4 " " 1.91 1.64 0.84 0.68
4-1/2 " " 1.35 1.16 0.59 0.48
5 " " 1.27 1.09 0.57 0.46
5-1/2 " " 1.06 0.91 0.47 0.38
6 " " 1.04 0.89 0.46 0.37
6-1/2 " " 0.53 0.45 0.24 0.18
Total....      17 fts 6 in 15 fts 0 in 7 fts 9 in 6 fts 3 in

The extension to which the level of various tall water from tide to
tide has shown in Fig tree. 7 [the footnote:  the Flat III.] that the embraces
one period of six months, and you/he/she is compiled by calculated heights
without taking account of possible troubles of wind.

The different differences between the night and tides in the morning I am
very clearly shown on this diagram;  in of the cases the night
tide is the tallest one, and in others the tide in the morning;  and while
to a duration every following tide is taller than the precedent,
to another duration the exposure of footsteps:  the set-back of the tide is
very marked. During the first part of the year the spring-tides
to new moon it was taller than that to the full moon, but toward June
condition was inverted. The influence of the position of the