I would like to add a few comments on this subject that have been
overlooked by others responding to this thread.

American carousels or merry-go-rounds, whichever you prefer, rotate
counterclockwise because this positions the rider's right side to the
outside of the ride.  Since most American carousels included a ring
machine when originally installed, the rider could grab the rings using
the right hand and hold on with the left.  This was preferred because
most people are right handed.

It was usually common practice to install standers (horses that don't
go up and down) on the outside row of the platform.  The ring game
could only be played by those riders on the outside row so the ring
game was a way to encourage folks to ride these horses and those who
did not care to catch the rings or were too small to reach the rings
rode on the jumpers on the inner rows.

If you should ever visit Knobles Grove in Pennsylvania where you can
still grab for the rings, most of the adult riders quickly go for these
horses.  European machines usually did not have the ring game so the
direction of rotation was not a consideration for that purpose.

As to the terms used, carousel and merry-go-round are interchangeable
and are generally used in America.  Direction of rotation or if the
animals are all horses or a mixture of beasts makes no difference.
The English use the terms gallopers and roundabouts with equal
discrimination as far as I know.  Elsewhere in the world, carousel,
or some derivative of that term, seems to be the norm.

Bob Moore
Orlando, Florida