Possible Clues:

• Pressure line on chart
• Line on a map connecting places of equal atmospheric pressure
• Thus I ban the same pressure along this
• Map line connecting points of equal pressure
• Weather forecaster's line of work?
• One thus secure in meteorologist's line
• Thus I prohibit the pressure, all the same, along it
• Is that the way I ban the pressure, all the same, along there?
• Michael Fish's go-between?
• (Map) line of constant atmospheric pressure