Relics of Stanley's journeys to be sold

His name is indelibly linked with the best-remembered catchphrase in the history of British exploration. "Dr Livingstone I presume?" inquired Sir Henry Morton Stanley after at last finding the missionary-explorer during his attempt to trace the source of the Nile.

Yesterday, 98 years after Stanley's death, a unique collection of personal relics relating to the former workhouse boy who became one of Britain's great African explorers surfaced in London, having been found in an attic.

Passed down by generations of his family, the collection – expected to fetch about £800,000 at auction at Christie's in London on 24 September – includes the water-stained map carried by Stanley on the 1874-78 Trans-Africa Expedition during which he traced the Congo to the sea. The map, with his pencil additions filling in the previously uncharted river, should fetch up to £15,000.

The Winchester rifle he was carrying when he found Dr Livingstone at Ujiji on Lake Tanganyika on 10 November 1871 is also among the hundreds of mementoes divided into 210 lots unearthed during a clear-out of two attics in the Surrey home of his family before the house was sold. It should realise £7,000 to £10,000.

One of the most poignant mementoes is a Turkish bursa, or pouch. The pillow, expected to fetch up to £5,000, is enclosed in a chintz pillow case and is accompanied by a note from his artist wife, Dorothy, reading: "This old cushion was valued by Stanley, he twice carried it across Africa – always using it as a pillow. He had great affection for this old cushion." A sextant presented to Stanley by Dr David Livingstone's daughter Agnes after the Scottish explorer's death in Africa in 1874 may fetch a similar price.

Piled high in the attic, untouched under dust sheets for more than a century, were a vast range of other relics, including spears, knives, bows and arrows, war axes, tribal paddles and barter goods.

Tom Lamb of Christie's, who has known of the collec-tion for 17 years, said it "sheds new light on the life of the poor, deserted workhouse boy who grew up to become one of the most important British explorers of all time".