Clause 4

The common seal of the Board shall bear such device as the Board may approve and such seal may from time to time be broken, changed, altered or made anew by the Board as it may think fit.

The common seal shall be kept in the custody of the President of the Board and shall be authenticated by the President of the Board or other member acting in the absence of the President of the Board and any document purporting to be sealed by the said seal and authenticated as aforesaid shall, until the contrary is proved, be deemed to be validly executed.