Young Red Haired Girl With Chains And The Ladder

Rigid ladders were originally made of wood,but in the 20th century tubular aluminium became more common because of its lighter weight. Ladders with fibreglass stiles are used for working on or near overhead electrical wires, because fibreglass is an electrical insulator.
Safety
For safety, a rigid ladder should be leaned at an angle of about fifteen degrees to the vertical. In other words, the distance from the foot of the ladder to the wall should be about one quarter of the height of the top of the ladder. At steeper angles, the ladder is at risk of toppling backwards when the climber leans away from it. At shallower angles, the ladder may lose its grip on the ground. Ladder stabilizers are available that increase the ladder's grip on the ground. One of the first ladder stablilizers or ladder feet was offered in 1936 and today is standard equipment on most large ladders.