Paul shares 2 interesting riddles

First riddle!!!!

black we are, and much admired
men seek for us if they are tired
we tire the horse,but comfort man,
tell me this riddle if you can.

Second riddle!!!!

old mother twitchet had one eye
and a long tail that she let fly,
and every time she went through a gap
she left a bit of her tail behind.

If you think you know the anwser you may write it down on a piece of paper please.