Both black freemen and slaves were renowned for their craftsmanship in such trades as bricklaying , iron grillwork , and carpentry .
黑人中的自由人和奴隶因他们在砌砖、铁花格、木工等行业中的精湛工艺而闻名。
Iron grillwork , designs for which were created locally and executed to a high perfection by slave craftsmen , decorates these balconies and also supports the roof .