From the National Archives, RG 109, Ch. 6, Vol. 8, "Orders, Letters, and Circulars Received, Chimborazo Hospital No. 5. 1863-64. 1 vol." p. 24
Chimborazo Hospital
Aug 30th 1863
Hereafter no Hospital Ambulance will be allowed to pass the guard of the Hospital after 8 o'clock PM and no carriage or Horse to pass into, or out of the hospital without a written order from the Surgeon in Charge of the Division to which the Ambulance belongs, or to which the carriage is going. Such orders are to be forwarded in all cases to this office for inspection.
Very Respectfully
J. B. McCaw
Surg. in Chief