What is "feather-bed"

Usage examples of "feather-bed".

Then came the Germans, and they also fought very bravely, so that one or two broke through the archers and came as far as the feather-bed, but all to no purpose.

They took and shoved the bag through a rip in the straw tick that was under the feather-bed, and crammed it in a foot or two amongst the straw and said it was all right now, because a nigger only makes up the feather-bed, and don't turn over the straw tick only about twice a year, and so it warn't in no danger of getting stole now.