their living conditions, but it also saw a change in the purpose of their stay, as they had no contact anymore with the outside world. Before this change, prisoners were only held until sentencing, and their stay in jail was relatively short and not considered part of their punishment. With abolishment of public displays of corporal punishment, there was no solution for convicted felons that were not suited for the workhouse. For these prisoners, imprisonment became their punishment, but there was no longer any need to house them near the courthouse or near the Grote Markt. This building could not house longer term prisoners and thus the jail function was moved. Sentinel post For a short period the Hoofdwacht was in use as a military hospital, where Antonius Mathijsen made his discovery of the orthopedic plaster cast in 1851. The upstairs was also the place where the watchmen would stand guard near the balcony. The church opposite had a sentry lookout posted in the steeple who could signal the guards on the balcony using red flags so that the guards in the Hoofdwacht could react to fires or other unrest. This sentry position was still in use in 1919. Since 1919 the building has been occupied by the Haarlem historical association , which uses it today for its meetings and small public exhibitions on the history of Haarlem. From May to September it is open to the public as a free "mini-museum" on weekend afternoons from 1:00-5:00 PM. References History on website of the Buildings and structures completed in the 13th century Buildings and structures in Haarlem History of Haarlem Rijksmonuments in Haarlem Museums in Haarlem History museums in the Netherlands