Marcus Aurelius in Yorkshire: the Ryedale Hoard

Back in 2020, a metal detectorist unearthed a small group of Roman objects now called the Ryedale Hoard. After several twists and turns it now seems that a wealthy enthusiast has bought the objects and placed them with the Yorkshire Museum.

The bust, which is 5 inches (13 cm) tall, depicts emperor Marcus Aurelius, who reigned from 161 to 180 AD. It has a socket in the base for attachment to a rod or scepter. The horseman may depict the god Mars, who was often shown in this way. The partial horse was the handle of a key. One theory is that the hoard represents items associated with the imperial cult that were ritually buried after Marcus Aurelius' death.

To me the most intriguing object is the plumb bob. 

The best guess is that it was part of a land surveying instrument called a groma. The Romans were a little obsessed with surveying. The word "groma" was also used for the center point of a military camp or town, laid out working from that point. The building of perfectly rectangular camps and perfectly straight roads was a symbol of Roman power; surveying the land was part of ruling it. You could imagine that this might lend magical associations to surveying, and that surveying instruments might end up being used for divination or casting spells. Sadly I can't find any evidence that this was so. But it certainly makes sense that a groma might be part of the gear deposited in a temple to a warrior emperor like Marcus Aurelius.