Bristol - part 1

My personal definition of Somerset Postal History goes up to the river Avon in the north - so the city of Bristol does not fall into Somerset - however some of the Receiving Houses in the Bristol Penny Post are in Somerset. I've also acquired a few other items of Bristol Postal History but I don't think I'm going to make a habit of this as Bristol's Postal History is enough of a subject to warrant collecting by itself !

Firstly a map of Bristol from 1832:

 

Then the earliest item I have from 1755 (the first handstamps in the British County Catalogue date from 1697):

Then a two-line dated handstamp from 1801 - I'm not entirely sure that I've got the calculations about the postage charge right, in particular there are some figures that are crossed out that I cannot work out:

And a type of handstamp that I think was unique to Bristol, a dotted circle handstamp.  Looking at the postal charge, the only way that I can work it out is if the post went over the Severn to Wales by ferry - did it do that in 1822 ??