Tarmac Group 1964, now group managing director, Martin acquired key quarrying assets, including Cliffe Hill Granite, Rowley Regis Granite and Hillhead Hughes. In 1968, Martin engineered the three way merger between Tarmac, Derbyshire Stone and the Scottish Asphalt company, William Briggs, creating the country's "largest roadstone and construction group". The group was briefly known as Tarmac Derby but the Derby name was later dropped. Further acquisitions were to come. Permanite, Britain's biggest roofing felt manufacturer, and Limmer, a quoted asphalt company, were bought in 1971, while the 1973 purchase of Mitchell Construction (which had foundered on the Kariba Dam) strengthened the construction
Cetacean surfacing behaviour Cetacean surfacing behaviour Cetacean surfacing behaviour or breaching is a group of behaviours demonstrated by the Cetacea infraorder when they come to the water's surface to breathe. Time intervals between surfacing can vary depending on the species, surfacing style or the purpose of the dive, and some species have been known to dive for up to 85 minutes at a time when hunting. In addition to respiration, cetaceans have developed and used surface behaviours for many other functions such as display, feeding and communication. All regularly observed members of the order Cetacea, including whales, dolphins and porpoises, show a range