Indian slaves were made a source of income to their owners by hiring them out to work in the same way as negroes and indentured white servants. The colonial laws in some instances made provision for such use. A South Carolina law of 1712 permitted an owner to hire out his slaves by the year or for a shorter time, and receive their earnings.[901] The provision was repeated in acts of 1735[902] and 1740.[903] Maryland, in 1753, provided that masters of ships might hire servants or slaves from their owners.[904] New York City, in 1731, made provision for owners hiring out negro and Indian slaves.[905] Since the custom was common in its application to other servile classes, one may believe that it was followed in other colonies besides those which made legal provision regarding it. The use of Indian slaves in military operations was not infrequent. In the New England wars Captain Church employed Indian captives against the enemy, a plan which he found serviceable on several occasions.[906] This use of Indian as well as negro slaves for military purposes was advocated in 1666 in a narrative addressed to the Duke of Albemarle.[907] In the intercolonial wars both negro and Indian slaves were captured by the French from the English army. In French records dealing with occurrences in Canada, under date of November 11, 1747, “four negroes and a Panis who were captured from the English during the war ...” are mentioned.[908] Still another possible proof of the use of Indian slaves by the English army is found in the Articles of Peace drawn up at Niagara, July 18, 1764. They contain the following: “Article 2nd. That any English who may be prisoners or deserters, and any negroes, Panis, or other slaves who are British property, shall be delivered up within a month to the commandant of Detroit, and that the Hurons use all possible endeavors to get those who are in the hands of the neighboring nations, engaging never to entertain any deserters, fugitives or slaves, but should any fly to them for protection, they are to deliver them up to the next commanding officer.”[909] That such slaves were put to practical use in the military preparations of the colonies, is seen in the New York City ordinances of 1693 and 1694 which provided that all persons, and all negro and Indian slaves that were not listed, should work on the fortifications.[910] Such a town action was not unusual. In 1638, the townsmen of Hartford, Connecticut, voted to levy on the cattle and slaves of the townspeople when needed for public service.[911]