There was a tracker in the force
Of wondrous sight (the story ran):—
He never failed to track a horse,
He never failed to find his man.

They brought him from a distant town
Once more to gain reward and praise,
Nor dreamed the man he hunted down
Had saved his life in bygone days.

Away across the farthest run,
And far across the stony plain,
The outlaw’s horse’s tracks, each one,
Unto the black man’s eyes were plain.

Those tracks across the ranges wide
Right well he knew that he could trace,
And oft he turned aside to hide
The tears upon his dusky face.

Now was his time, for he could claim
Reward and praise if he prevailed!
Now was the time to win him fame,
When all the other blacks had failed.

He struggled well to play his part,
For in the art he took a pride.
But, ah! there beat a white man’s heart
Beneath his old, black wrinkled hide.

Against that heart he struggled well,
But gratitude was in the black—
He failed—and only he could tell
The reason why he lost the track.

Henry Lawson

http://www.poemhunter.com/poem/the-black-tracker-or-why-he-lost-the-track/