Modern central heating is disastrous for many antiques, certainly in combination with insulation measures. 'In dry winters the humidity in the house sometimes drops to 20 percent, while for antique furniture the optimum is between 65 and 70 percent.' The consequences are clearly visible in the courtyard: a newly arrived walnut cabinet with warped panels, an eighteenth- century sideboard with cracking and peeling veneer, a rickety seventeenth-century desk made of rosewood. 'The parts of this desk fall apart due to dehydration. The furniture is glued with bone glue, as was customary for centuries. The beauty of bone glue is the reversibility: as soon as the moisture content increases, the adhesive effect also returns. 'All these' defects' are easy to restore. It is worse if objects are 'abused' to speak in the terms of Alexander. He is referring to wrongly executed restorations, a phenomenon that is all too common.