Riddle me this:
I am rotund and one with a barrow,
Though you must take out only the first,
In the name of the youngest pharoah,
Otherwise, my shape is accursed.
I can stroll and am two with a chair,
But again, you must take out the first;
Though this time it comes in a pair,
In which stillness cannot be coerced.
I will carry you and never tire,
For quite a long period of time.
My invention was vital like fire,
And I burn, too, but never through crime.
As with fire comes killing of air;
With a flame might come killing of wax.
But for me, I may come with a spare,
Though I also might leave with my tracks.
If you exchange only one letter,
Then the answer will be much revealed;
Though it must take somebody quite clever,
For a similar word has been sealed.
What am I?
The answer is just one word.
Can you find it? Hopefully.
Every line is a clue, none excluded.
Each paragraph is an explanation.
That includes the title — every line!
Edit:
Added the word "much" to the second line in the last paragraph, namely,
Then the answer will be revealed
for the syllables match better when spoken, thus making the rhyme sound better too.