This compact star cluster has been called a compressed open cluster and a globular. At 165X on a good night, I can see an arrowhead shape to the cluster and count 56 stars across the mottled face of this cluster. There are many curving lines of stars with dark lanes between them. Both of these large, long focus scopes would show about 100 stars resolved. NGC 6879 is pretty bright, very small, not brighter in the middle.
Averted vision makes it grow.
Pretty bright, very, very small, little elongated. Seeing as how all the bright and easy globulars had been discovered by 19th century observers, these are all quite difficult objects to spot. It is just a grainy spot at all powers. Harvard 20 is an open cluster found on the survey plates taken at the turn of the century by the Harvard Photographic Patrol. It is pretty faint, pretty small and elongated.