Ardgowan Hotel, located at Playfair Terrace on North Street, was built in 1847. During World War II it served as an army headquarters to many soldiers from British army however also First Polish Army which was stationed in St. Andrews. Józef Kosacki was a signals officer of the First Polish Army which was stationed in the town until 1943.

One day an awful tragedy happened: a mine explosion on the beach in Arboath killed two Polish soldiers. The accident prompted Kosacki to prevent such accidents in the future. Before World War Two started, Kosacki has been working in the Special Signals Unit in Warsaw where he worked on electronic appliances for the army. Using his electrical engineering knowledge from work and university, Kosacki started working on his new project – a portable mine detector.

After three months Kosacki came up with a portable mine detector prototype that successfully detected coins previously scattered around West Sands which served as a testing site. One year later, in 1942, the portable mine detector was used in combat for the first time during the Second Battle of El Alamein, and since then around five hundred detectors were issued to the army as they doubled the speed at which mined sands could be cleared, accelerating the speed from 100 to 200 meters an hour.

The mine detector worked thanks to a bridge wire which balance was disrupted every time the device was in the surroundings of metal objects. The radio waves coming from the wave generator at audible frequency interact with the metal objects, which could be heard with headphones attached to the bridge’s coil – this way a soldier could hear whether a potential mine is close or far. The mine detector was also quite light (14 kg /30.8 lbs) which make it considerably easier to use. It was used during the Allied Invasion of Sicily, invasion of Italy and the Invasion of Normandy.

Kosack has never patented his invention; instead, he handed it to the British army free of charge for which he received a congratulations letter from King George VI. The portable mine detector was commonly used until the end of 20th century.