Monica Walker, engagement manager, displays a surgeons knife used in Victorian surgery, in The Old Operating theatre of St Thomas' Hospital in London, Tuesday, April 11, 2023. The Old Operating Theatre, Europe's oldest surviving surgical theatre is re-opening to the public on April 21. The museum is reopening after having its pyramid skylight refurbished, the skylight made countless operations possible as electricity was not yet in use between 1822 and 1862. (AP Photo/Kirsty Wigglesworth)