FIG. 1 is a perspective view of a towel bar showing my new design; FIG. 2 is a front elevational view thereof; FIG. 3 is a top plan view thereof; FIG. 4 is a right side view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a bottom plan view thereof; and, FIG. 7 is rear elevational view thereof. The towel bar is shown broken-away in the views to indicate indeterminate length.