Madam, – In your report on the opening of the visitor centre of Cathal Brugha Barracks (Home News, May 6th), you describe Cathal Brugha as chief of staff and minister for defence. Brugha was never chief of staff nor was he in the Army at any time. He was minister for defence in the two Sinn Féin Dáils from April 1919 to January 1922. Mulcahy was chief of staff from March 1918 until January 1922 and again from June 29th, 1922, to late August 1922, when he succeeded Michael Collins as commander in chief. The roles of Brugha and Mulcahy are often misunderstood because of errors included in the Béaslaí biography of Collins published in 1926 and in subsequent works. Mulcahy succeeded Brugha as minister for defence from January 1922 to March 1924, when he resigned at the time of the Army Mutiny. – Yours, etc,