'James Merriman Archer Thomson' (
1863-
1913) was a British rock-climber and mountaineer.
He climbed extensively in North Wales with others such as
Oscar Eckenstein. He was a believer in leading on sight, and was not keen on
O. G. Jones's practice of surveying a route with a top-rope. He extensively explored the cliffs of
Y Lliwedd, and with
A. W. Andrews produced the first official climbing guide to the cliff (published by the then-recently-founded
Climbers' Club) in 1909; he authored the second, to the
Ogwen District, the following year).
From 1896 until his death (by suicide?) in 1913 he was Headmaster of Llandudno County School.