J. M. Archer Thomson

James Merriman Archer Thomson (1863 to 1912) was a British rock climber and mountaineer who climbed extensively in North Wales, with partners such as Oscar Eckenstein. He believed in leading on sight and was not keen on the practice of O. G. Jones of surveying a route with a top-rope beforehand. He explored the cliffs of Lliwedd in depth, and in 1909, with A. W. Andrews, he produced the first official rock-climbing guidebook to that cliff, published by the then recently founded Climbers' Club. The following year he wrote the second Climbers' Club guide, to the Ogwen District. From 1896 until his death in 1912 he was headmaster of Llandudno County School. He died by suicide, drinking carbolic acid.