Military Laws And Rules And Regulations For The Armies Of The United States.
Adjutant and Inspector General’s Office Washington, May 1st , 1813
Art. 61. Officers having brevets, or commissions, of a prior date to those of the regiment in which they serve, may take place in courts martial and on detachments, when composed of different corps, according to the ranks given them in their brevets or dates of their former commissions; but in the regiment, troop or company, to which such officers belong, they shall do duty, and take rank, both in courts martial and on detachments, which be compsed only of their own corps; according to the commission by which they are mustered in the said corps.
Art. 62. If upon marches, guards, or in quarters, different corps of the army shall happen to join, or do duty together, the officer highest in rank of the line of the army, marine corps, or militia, by commission there, on duty, or in quarters, shall command the whole, and give orders for what is useful to the service, unless otherwise specially directed by the President of the United States, according to the nature of the case.
Art. 63. The functions of the engineers being generally confined to the most elevated branch of military science, they are not to assume, nor are they subject to be ordered on any duty beyond the line of their immediate profession, except by the special order of the President of the United States; but they are to receive every mark of respect, to which their rank in the army may entitle them respectively, and are liable to be transferred, at the discretion of the President, from one corps to another, regard being paid to rank.
Art. 64. General court martial may consist of any number of commissioned officers from five to thirteen inclusively, but they shall not consist of less than thirteen, where that number can be convened, without manifest injury to the service.