Possible Clues:

• A line on a chart is nothing to the legal profession
• Thus I apply the same pressure to keep this out
• Showing pressure or bias is out of order
• A sign of pressure when one thereupon heads for drinking hole!
• What's shown on some maps is pub - inscribed circle
• Line on map indicating barometric pressure
• Thus I get to the pub and get the same atmosphere there
• Is pub after zero pressure consistent here?
• Line on map connecting areas of equal pressure
• I 'cry a river' -- it shows you the pressure!