182 
MR. LLOYD ON THE DIFFERENCE OF LEVEL BETWEEN 
The pickets used for the stations were also of a larger class than those used 
in other parts ; but the ground was occasionally so spongy, that it was with 
much difficulty that a picket could be driven, and frequently the iron heads 
of several would break off, before we could succeed in getting one down. 
It will be seen by the Observation-book, that from a mean of pickets (page 
5 to 11), the Queenborough and Sheerness marshes are in some parts 6.3652 
below the northern standard; but these marshes are unlike the rest passed over, 
being particularly rugged and undulating. 
In the commencement of the marshes between St. James and Yantlet Creek, 
it appears by a mean from picket 11 to 17, that the surface of the marshes is 
5.8524 below the standard, or 1.7863 below mean spring tide high-water mark ; 
and opposite Allhallows, by a mean from picket 35 to 44, the marshes are 
3.7247 below the north standard, rising there 5.8524— 3.7247=2.1277- 
About half a mile past the Decoy in St. Mary’s marshes, nine miles distant 
from Sheerness, the marshes again fall : the mean from picket 75 to 86 gives 
5.9916 below the north standard at Sheerness, and 5.9916— 4.0661 = 1 .9255 
below mean spring tide high-water mark. 
Some distance past Cliff Canal, and between that and the Gravesend Canal, 
in Higham marshes, by a mean from 120 to 124, the surface is 6.6356 below 
the north standard, which —4.0661 gives 2.5695 below spring tide high-water 
mark, having fallen in a distance of seven miles and a half 2.9109, and in a 
distance of five miles 0.6440 ; the marshes between Northfleet and Green- 
hithe, by a mean from picket 208 to 211, are 7-4889 below the north stand- 
ard, and —4.0661 =3.4228 below spring tide high-water mark. 
On the eastern side of Dartford Creek, the marshes, by a mean from picket 
247 to 252, are 8.8676 below the north standard, therefore 8.8676 — 4.0661 
= 4.8015 below spring tide high-water mark. 
On the western side of the marshes, as far as the mean from picket 256 to 
259 will show, the marshes are 9.7207 below the north standard, and 5.6546 
below spring tide high-water mark, and lower by 0.8531 than the marshes 
on the eastern side of Dartford Creek. 
The marshes to the eastward, and in the immediate vicinity of the arsenal at 
Woolwich, are (from a mean of pickets 305 to 312) 10.1404 below north 
standard, and 6.0743 below spring tide high-water mark, and only 3.0107 
above the mean level of the sea. 
