In 1878 Maxwell, at the request of the Vice-Chancellor, delivered the Rede Lecture in the Senate-House. His subject was the telephone, which was just then absorbing a considerable amount of public attention. This was the last lecture which he ever gave to a large public audience. It was during his tenure of the Cambridge chair that one of the cottages on the Glenlair estate was struck by lightning. The discharge passed down the damp soot and blew out several stones from the base of the chimney, apparently making its way to some water in a ditch a few yards distant. The cottage was built on a granite rock, and this event set Maxwell thinking about the best way to protect, from lightning, buildings which are erected on granite or other non-conducting foundations. He decided that the proper course was to place a strip of metal upon the ground all round the building, to carry another strip along the ridge-stay, from which one or more pointed rods should project upwards, and to unite this strip with that upon the ground by copper strips passing down each corner of the building, which is thus, as it were, enclosed in a metal cage. After a brief illness, Maxwell passed away on November 5, 1879. His intellect and memory remained perfect to the last, and his love of fun scarcely diminished. During his illness he would frequently repeat hymns, especially some of George Herbert's, and Richard Baxter's hymn beginning "Lord, it belongs not to my care." "No man ever met his death more consciously or more calmly."