The poem about the Tay Bridge was written by The Great McGonigal, a Scot, who was a very bad actor and a terrible poet (as you can see) frequently referred to as the world's worst poet. He was unpopular in the late 1800s as I recall. It's rumored that Prince Phillip has his collected his complete works. He was a for real person.
    Legend has it that he once appeared onstage in Glasgow as Hamlet. When it came time for Hamlet's death scene, he couldn't stand the idea of leaving the stage so he stretched the death scene so far people in the audience shouted "Lie doon, McGonigal, lie doon!'

O'Meara