Abstract: Electronic fence surveillance apparatus in which a plurality of sections of relatively rigid electrical conduit are supported by the fence serially therealong and independently of the fence posts, the sections being connected by a plurality of liquid tight housings each interposed between and having a threaded liquid tight connection with the adjacent sections of conduit and in which there is a vibration sensor secured in each of the housings and responsive to vibrations transmitted to the housing in which it is located, each of the vibration sensors being effective to produce a vibratory electrical signal upon the conduit being vibrated and transmitting this signal to an indicating device through an electronic network. The vibration sensor is in the form of a piezoelectric element designed to operate within the range of frequencies occurring in the conduit when the fence is disturbed. The conduit is preferably of iron or steel and has a wall thickness of between 0.10 and 0.