above and below London Bridge. 53 



The ebb of these tides produced slack water at the bridge 

 about 30 minutes after high water, and then gradually sunk to 

 their greatest fall at low water. 



The time of high water, October 21 st and 23d, was the same 

 below as above bridge ; but the average time of high water 

 spring tides is 9 minutes earlier below than above bridge. 



The flood of neap-tide, October 30th, produced slack water 

 through the bridge, in about two hours after low water below 

 bridge, when there was some land-flood in the river ; from which 

 time a head gradually increased below bridge to 1 foot 3 inches 

 at two-thirds flood, and then regularly decreased to 4 inches at 

 high water. 



The first flow of this tide, nevertheless, began above bridge 

 about 1 hour after low water below bridge, although the water 

 was then 1 foot higher above than below bridge ; but the aver- 

 age time of low water below bridge is 32 minutes earlier than 

 above bridge. 



The ebb of this tide produced slack water at the bridge about 

 15 minutes after high water above bridge, and then gradually 

 sunk to its greatest fall at low water. 



The time of high water, October 30th, was 15 minutes earher 

 below than above bridge ; and the average time of high water 

 neap tides is 15 minutes earlier below than above bridge. 



