Yes, that's what they are [carbon], and probably the size and
hardness of the brushes [is selected] as to control wear.  Brass Ring
Entertainment sells parts and service.  Without more info it would
be hard to suggest something to replace them.

Brass Ring is in Sun Valley, Calif., www.carousel.com  Carousel Magic
in Ohio also may be able to help: www.carouselmagic.com

Also a group that the carousel owner should belong to is the National
Carousel Association, c/o Terry Blake, P.O. Box 4333, Evansville, IN
47724-0333  www.nca-usa.org  They have a tech group for owners/operators
and have info books on upkeep and fund raising, etc., for antique
carousels.  Hope this helps.

Glen R. Perye Jr.