A process in nature in which organisms possessing certain genotypic characteristics that make them better adjusted to an environment tend to survive, reproduce, increase in number or frequency, and therefore, are able to transmit and perpetuate their essential genotypic qualities to succeeding generations.
A watchglass can be used as a beaker cover, but you can also place small amounts of chemicals on it and then heat it (for example, to evaporate some water from a wet chemical). From Wikipedia: A watch glass is a circular, slightly concave piece of glass used in chemistry as a surface to evaporate a liquid, or as a cover for a beaker. The latter use is generally applied to prevent dust or other particles entering the beaker; the watch glass does not completely seal the beaker, and so gas exchanges still occur.
Quartz watches are analog timepieces that run on a tiny, vibrating, electrified quartz crystal. They keep extremely accurate time (within a minute each year). Mechanical watches are powered by a complex array of gears and springs. These watches can command a hefty price as a result of their superior craftsmanship. Unfortunately, the ancient art of hand-wound watchmaking remains imperfect. Mechanical watches lose about an hour a year and must be wound regularly.