The two meanings of the word camera, though apparently quite different, are closely linked historically, both deriving from Latin camera, ‘vaulted roof or chamber’, also the root of English chamber. Camera entered English in the 17th century in the sense ‘legislative chamber’, and is still used in the phrase in camera, now meaning ‘in private chambers’; the Latin sense is also retained in names such as that of the Radcliffe Camera, the circular domed building which forms part of the Bodleian Library in Oxford. The application of the word to the device for taking photographs dates from the earliest years of photography; the precursor of the cameras of today was the camera obscura or ‘dark chamber’.