To protect their business, homes, automobiles, and the possessions therein, owners enlist the help of burglar alarms. Functioning as a type of invisible guardian, devices to scare away thieves or alert authorities have been around since antiquity. The first modern burglar alarm was one of thousands of innovations developed at the outset of the Industrial Revolution in eighteenth-century England. The English inventor Tildesley is credited with inventing the burglar alarm. His model mechanically linked a set of bells to a door lock. When an intruder attempted to open the lock with a skeleton key or other device, the chimes would sound. The commotion caused by the ringing bells would attract attention and cause the intruder to flee. Similar alarms were developed in the American colonies around this time.

The next major innovation in the burglar alarm was the addition of electricity. In the 1850s, Boston inventor...