.Chapter 1 made clear that during the early Bangkok period, control exercised over manpower had shifted more and more towards the nai at the expense of the king And the number of phrai som was growing. When corvée was commuted to money payment,revenues tended to be monopolized by the chao mu (head of the manpower unit) and did not pass to the state in spite of many efforts to reform the system. During the reign of king Rama III. The service fees paid by the pharai som and for the that (by their nai) were commuted to three. And one-and-a-half bahts respectively. When this failed to guarantee state revenue, a new formula was implemented. This formula calculated fees according to the time of service each person owed the government. Thus phrai luang, who had to three months’ corvée, had the option of paying eighteen bath; phrai som who owed one monthpaid six bayh; khun mun (petty officials) paid four four baht for twenty days’ corvée, whereas that could pay one-and-a-half bath in lieu of eight days’ corvée