The problem of synchronizing clocks at a distance has been solved both by the use of travelling clocks (e.g. caesium beam devices) and by radio transmission of time signals, for which active satellites are used to overcome inherent errors. A group of Czech workers recently developed a method of intra-continental clock comparison which makes use of the properties of domestic television signals. This has been verified under Australian conditions in experiments carried out between Mount Stromlo Observatory and the Division of Applied Physics of the National Standards Laboratory, CSIRO, Sydney, using signals from the Australian Broadcasting Commission transmitter ABWN 5A Wollongong.