Thanks everybody! It would seem that the wall is bothering most of you and I don't doubt that you are right. There is some tone on the wall in patches (not evident in the scan) as it is badly plastered - you can see some of the plaster has come away by the door post. Also, as would happen, the plastered corner has been damaged over the years, exposing the brickwork beneath.There is a degree of shaping and detailing on the corner that is not evident in the scan. Some is left sharp where plaster has been chipped off (such as by the swallow) and in other places (above the tap) the broken edge of the plaster has been worn smooth.
However, I'll attend to that wall tomorrow and let you see how I got on. My one concern is that if I add an overall tone to the wall, it might kill the shadows by lessening the contrast. On the other hand it might serve to brighten the dogs? I'll give it a try.
<<some deeper shadows and slightly lighter tones on the objects within the shadows. I'm currious if you went about this in layers until reaching suitable dark tones and using blu-tac where needed or if you used a differnt method to best achieve this?>>
Shelby: I pushed the tones to a level just below that which I thought I would need to display the bird. Then, with the bird drawn, I added further layers until the bird was sufficiently pushed forward. The bird is a little more noticeable in the original than it appears in the scan.
<<...the contrast between the tail of the right hand dog and the thing in the background; they seem to blend together too much and I think would look better if the 'thing' was darker.>>
Bob: The "thing" is one of Badger's hind legs (he's our carriage driving horse). I thought I would agree with you but I now prefer it as it is. If the tail was too prominent I think it would direct the eye where I don't want it to go. By leaving it a bit muddled I know I'm making the viewer to sort it out - but aren't many things in life like that? I decided the visual problem was easily resolved so I left it as a "reality". However, Badger's legs are in relative shadow so I could (and might) tone them down a bit more.
<<...the contrast between the wall and the objects in the background is so great that it appears the edge of the wall is a sharp corner, which given the non-linear edge seems unlikely. To me, it seems like there should be more "texture" on the edge of the wall in a few areas to show the wear that causes the non-linear edge.>>
Eye-fly: Maybe these details will help resolve your concern? I accept your point... but you haven't seen our house! Take the plaster off the walls and NOTHING is linear!
The indentations in the plaster edge are not quite as dramatic as they seem. You can just make out in the scan that an edge of exposed brickwork exists? This gives the true edge of the wall with a thickness of plaster remaining in certain sections.
<<One thing I love about your drawings Mike is the amazing ability you have of putting the imagination of movement and smell in you work! I can see the two dogs tails moving and I can even smell their fur..... >>
Bella: I really don't know what to say. That must be one of the nicest compliments I've ever been paid. Suddenly I'm liking this drawing a whole lot better than I was..... 
MIKE
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