Vacuum cleaner magnate James Dyson has angrily resigned from his position as board chairman of London’s Design Museum, declaring that the institution is “ruining its reputation” and “betraying its purpose”. Dyson had been in a years-long feud with director Alice Rawsthorn over the true mission of the museum, and his resignation letter accuses her of allowing it to “become a style showcase [when it should be] upholding its mission to encourage serious design of the manufactured object.”