The Two Dogs and the Dead Ass La Fontaine's fable

Two lean and hungry mastiffs once espied
A dead ass floating on a water wide.
The distance growing more and more,
Because the wind the carcass bore,—
“My friend,” said one, “your eyes are best;
Pray let them on the water rest:
What thing is that I seem to see?
An ox, or horse? what can it be?”
“Hey!” cried his mate; “what matter which,
Provided we could get a flitch?
It doubtless is our lawful prey:
The puzzle is to find some way
To get the prize; for wide the space
To swim, with wind against your face.
Let’s drink the flood; our thirsty throats
Will gain the end as well as boats.
The water swallow’d, by and by
We’ll have the carcass, high and dry—
Enough to last a week, at least.”
Both drank as some do at a feast;
Their breath was quench’d before their thirst,
And presently the creatures burst!
And such is man. Whatever he
May set his soul to do or be,
To him is possibility.
How many vows he makes!
How many steps he takes!
How does he strive, and pant, and strain,
Fortune’s or Glory’s prize to gain!