Activity and sales slowed in the eastern spruce lumber market yesterday. The weight of supply from the eastern mills came to bear on the market. Demand, although good, was not enough to offset the steady production from the eastern mills. Prices were suspect but resistant to change on the often-traded items such as studs and random dimension. The mills banked on orders they had garnered recently to hold off adjusting, at least for the moment. More affected and opportunistic were the low-grade items on which the mills have had more difficulty in finding sales.