186 
MR. LLOYD ON THE DIFFERENCE OF LEVEL BETWEEN 
I next levelled to a standard placed at the West India Docks on the S.S.E. 
side, close to the entrance. This standard is 1.3018 above the northern stan- 
dard, and 2.3367 above the index mark xxm. Therefore 2.336 7 — 1.3018 = 
1.0349, the index mark below the north standard at Sheerness, and 4.0661 — 
1.0349 = 3.0312 is the height of xxm above mean springtide high-water mark 
at Sheerness. 
Not having succeeded in procuring a copy of the observations on the tides 
at the West India Docks, I cannot make any other comparison. 
At the Regent’s Canal Dock, in a very large stone near the office of the canal 
works (see page 26), I placed another standard mark. This standard is 2.4418 
above the northern standard at Sheerness, and 2.2308 above the index mark 
xxi ; therefore the index is 0.21 10 above the north standard at Sheerness. 
From two years’ observations on the tides (1828 — 1829), the following are 
the results. 
Mean Spring Tide High-Water Mark for 
1828. 
1829- 
Spring Tide, 
High Water. 
High Water, 
Neap. 
Spring Tide, 
High Water. 
High Water, 
Neap. 
Ft. In. 
Ft. In. 
Ft. In. 
Ft. In. 
January 
19-8 3 
15. 
19-1 
14.8 
February 
18.11 
14.3 
19.1 s 
13.11 
March 
19-9 
14.3 
19.5 
14.8 
April 
19-9 8 
14.3 
19-6 
13.7 
May 
18.9 
15.5 
19- 
14.9 
June 
18.10 
15.7 
18.9 s 
15.2 
July 
19-2 6 
15.9 
18.9 5 
15.7 
August 
19-3 
15.4 s 
19-3 
14.7® 
September 
19-9 
14.6 
19-7 
14.7 
October 
19-7 
14.5 
November 
19-1 5 
143 
19-3 
14.3 
December 
19-2 J 
13.9 
18.7 
14.9 
Means 
19-325 
14.733 
19-141 
14.592 
Spring 1829 19-141 Neap 1829 14.592 
1828 19-325 1828 14.733 
Mean Spring Tide for two years 19.233 Mean Neap Tide for two years 14.662 
Mean Spring Tide 19-233 
Mean Neap Tide 14.662 
Mean High Water 
16.947 
