  The concept of the brush number $b_r(G)$ was introduced for a simple
connected undirected graph $G$. The concept will be applied to the Mycielski
Jaco graph $\mu(J_n(1)), n \in \Bbb N,$ in respect of an \emph{optimal
orientation} of $J_n(1)$ associated with $b_r(J_n(1)).$ Further for the
aforesaid, the concept of a \emph{brush centre} of a simple connected graph
will be introduced. Because brushes themselves may be technology of kind, the
technology in real world application will normally be the subject of
maintenance or calibration or virus vetting or alike. Finding a \emph{brush
centre} of a graph will allow for well located maintenance centres of the
brushes prior to a next cycle of cleaning.
