Correspondence and papers regarding celebrations for the 150th anniversary of the Cape Observatory, including details of arrangements for the two days of celebrations; lists of scientific, diplomatic and civic guests; an office notice detailing the arrangements for the V.I.P. Visitation of the 4th December and Public Open Day on the 5th; correspondence with various outside parties requesting attendance, and with the Royal Greenwich Observatory asking for material for the exhibition; letters and telegrams of congratulation from those unable to attend, including the Revd R. Woolley; and copies of letters of thanks sent to individuals for their efforts over the celebration period.