The Tryall Waterwheel was built around 1700 and is still functioning today. Water supplied by an aqueduct carries water from the Flint River for two miles down through the hills to the waterwheel. The aqueduct was built by slaves using a mixture of marl, ox blood and animal hair as cement and cut limestone blocks.
The use of slaves was not limited to the waterwheel. British colonists in the mid 17th century started to build profitable plantations and trading routes. The engine for these was not the waterwheel but the labour of slaves. In fairness to the current owners of the Tryall Estate, they do not shy away from this aspect of the area’s history (see link below).
The other element of the stamp is the group of musicians. The sign in the foreground reads “The man who plays the banjo in this small calypso band is unfortunately blind. The players have been instructed not to approach anyone for payment, but if you choose to place a donation in the box, it will be appreciated by them.” That sign was itself only legible by taking a photo and zooming right in; at postage stamp size, it’s just a jumble.