In early 19th century, grave robbing became a growing concern, especially in Scotland, as robbers used to steal the dead bodies and supply the corpses to medical students, for dissection studies. This is how the idea of contraption cages over graves came up – to protect the dead bodies from being stolen.
Many people were determined to protect the graves of newly deceased friends and relatives. The rich could afford heavy table tombstones, vaults, mausolea and iron cages around graves. The poor began to place flowers and pebbles on graves to detect disturbances. They dug heather and branches into the soil to make disinterment more difficult. Large stones, often coffin-shaped, sometimes the gift of a wealthy man to the parish, were placed over new graves. Friends and relatives took turns or hired men to watch graves through the hours of darkness. Watch-houses were sometimes erected to shelter the watchers. One watch-house in Edinburgh is a three-storey castellated building with windows. Watching societies were often formed in towns, one in Glasgow having 2,000 members. Many kirk session houses were used by watchers, but graves were still violated.
These mortsafes were either cages or grills placed over the graves of newly deceased people during the 19th century, and were made of varying materials, typically from iron or stone. It’s a common myth that these cages were built to keep the undead from rising, but that’s not true. The cages were built to keep out, not in.