From “Mountaineering in the 1800s – The Correct Equipment and Outfit” by C.T. Dent
“Knickerbockers are now generally in vouge, and have many advantages; they alow free movement of the knee, and do not get so draggled and dirty as trousers. A disadvantage is that they entail wearing long stockings, which take up more room in the knapsack. In ordinary knickerbockers a cloth continuation is provided, which fits close to the upper part of the leg; if this continuation is made to turn up, instead of down, as usually worn, the upper part of the stocking can be folded over it, and kept up perfectly.”
and this not-so-sublte dig at inelegant climbers:
“Some advise that the knickerbockers should be double seated. The necessity for this depends on the climbers habitual mode of progression when descending rocks. The precaution ought to be unnecessary.”