gathered together in large groups, and unrestrained by substantial mental instruction, the _Ajem-oghlans_ were by no means easy to manage. They frequently raised great disturbances in the city, in emulation perhaps of the Janissaries.[253] Those who wished were allowed to learn to read and write, but they were not obliged to do so.[254] They received a small amount of pay, with food and clothing.[255] After a certain time spent in this stage of development, the majority of the _Ajem-oghlans_ were assigned, one by one as each seemed ready, to the service of the _odalar_, or messes, of the Janissaries.[256] The latter then became responsible for their training in the art of war, and discharged this duty with much zeal. In the course of time, as the _Ajem-oghlans_ acquired sufficient skill, and as vacancies occurred, they were enrolled as full-fledged Janissaries.[257] The gardeners of the sultan’s palaces and the palace servants seem not ordinarily to have become Janissaries, but to have been advanced toward the directing of the transport, commissary, and artillery services, the oversight of the imperial stables, and like positions in the administration of the army and the great household.[258] No doubt some of those assigned to the fleet were promoted in the navy, but most of them seem to have become Janissaries.[259] Thus a large number and variety of openings lay before the _Ajem-oghlans_, who as they became ready were advanced into them. The ordinary age of graduation from the corps was twenty-five years,[260] which may be regarded as the age of majority for all the sultan’s slaves. At times war caused such depletion of the upper service that _Ajem-oghlans_ were promoted before they had reached the desired age or were thoroughly ready.[261] ADVANCEMENT BASED ON MERIT The entire system from start to finish was designed to reward merit and fully to satisfy every ambition that was backed by ability, effort, and sufficient preparation. Two parallel lines of reward were established, the honorable and the financial. In the page school the first was represented by promotion from class to class, and, in the case of those who were observed to be the most suitable, by advancement through the chambers of personal service to the _Khas Oda_. In this _oda_ they were promoted in regular order through the twelve or more special offices.[262]