Brighton Suspension Pier.
Engraved by Edward Fox and published byC. & R. Sicklemore c..1820.

These three prints were made from the same plate.  The engraved detail is the same in all three, but the difference is in the way they were printed and finished.
a. is shown in the state directly after printing, without any hand finishing.  It was printed in blue and brown.

b. was also printed in two colours, and then hand finished.  The added colour is mainly to the left side of the picture, to the buildings, the foreground and the people.  To the right, the only additional colour is to the boats and the flag.  The difference in the blue ink used is noticeable, much richer in b.

c. was printed entirely in black; all the colour was added by hand.  The difference can best be seen in the sky and the sea, a dull effect compared to the brilliance of b.  The picture becomes a dark stormy day.

In terms of value, b. is worth about twice c.  a. is more of the novelty than a quality item, valued somewhere between the other two.