This is a tale of three islands - Noss, Bressay and South Georgia - and of two Shetland islanders whose lives spanned 120 degrees of Atlantic latitude, from Shetland at 60 degrees North to the South Shetland Islands at 60 degrees South.
Jessie Jamieson and Tammie Laurenson were born in the first decade of the 20th century. Jessie's father, Jimmy, was a shepherd from Britain's most northerly island, Unst. Jessie was one year old when her parents moved to the Isle of Noss and stayed there until 1939. They were the last people to live all year round on the famous nature reserve island.
Tammie's father and grandfather, both also christened Thomas, were merchant seamen from the croft of Gorie in the neighbouring island of Bressay, so Jessie and Tammie would have known each other from childhood.
'Tammie o' Gorie' went to sea at 18 and spent many seasons with the Salvesen whaling company on the coast of Antarctica, also sailing 'deep sea' to South America, Canada and the Far East. He was the officer commanding the defence of Leith Harbour in South Georgia during most of the Second World War, and later served as mate on ships sailing between Aberdeen, Lerwick and the North Isles of Shetland.
In contrast to her husband's world travels, Jessie seems to have left Shetland only once - to be married at Edinburgh in 1936 after a 12-year courtship. She spent her whole life as a shepherdess and crofter in Noss and Bressay but she had a benign influence on family and friends far beyond. She carried in her head a vast store of knowledge about local natural and human history, place names and folklore. Jessie was also a crack shot with a rifle, a skilled fisherwoman and a devoted gardener.
The author, who first met the Laurensons as a schoolboy birdwatcher in 1962, recently renovated their old house at Gorie after it lay empty for 30 years. He was inspired to write this double biography when he found Jessie's diary and her mother's Noss visitors' book in the loft of the house - and when a biscuit tin full of their old photographs turned up in Glasgow among the effects of one of Jessie's deceased relatives. The pictures cover a century of Shetland crofting life, Merchant Navy history and the now defunct Antarctic whaling industry.
'Sixty North to Sixty South' is illustrated with many images from this remarkable collection, some portraits of the Noss family taken in 1933 by the great Dutch photographer Jan Strijbos and pictures by the author.