Plunge pool softer or fractured rock has been eroded back to a knickpoint, water continues to bombard its base. Because this rock is often less resistant than overlying strata, the water from the higher elevation continues eroding downward until an equilibrium is achieved. A somewhat similar bowl-shaped feature developed by flowing water, as opposed to falling water, is known as a scour hole. These occur both naturally and as a result of bridge building. Plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It
Dropping funnel glass tube from the bulb of the funnel, to the ground glass joint around the stem. These replace the liquid volume lost in the bulb with the equivalent gas volume from the flask into which the reagent is flowing, and are useful when handling air-sensitive reagents in a sealed, inert-gas environment. Without this tube, or some other means to equalize the pressure between a sealed receiving flask and the bulb of the funnel, the flow of fluid from the bulb will rapidly come to a halt. Dropping funnel A dropping funnel is a type of laboratory glassware used to transfer