I had the misfortune of setting next to a man on the tube this morning who wouldn't stop coughing. Every few seconds, he would make a feeble attempt to clear his throat, stop and then start again. I suspect he had one of those irritating ticklish coughs that cause you involuntarily to cough without warning but which aren't really cleared by the act of coughing.
Either way, it annoyed me.
After he had coughed for the fifth time, I could take no more so I summoned every ounce of Englishness from my body and did the proper thing. I glared at him.
Miracles! He promptly stopped coughing and I didn't hear a peep out of him until I alighted at Embankment.
I think I should patent my glare before somebody else does.