Hobbies And Interests
Barometers
Everyone knows thermometers, but these are limited to the current state of the weather, telling very little about the future state. Barometers on the other hand, are much more useful as a tool for prediction. Measuring air pressure, barometers date back to the 17th century. Changes in air pressure are significant because severe alterations are indicative of coming storms. If air pressure is on the rise, dry conditions are imminent; if air pressure falls, stormy conditions are likely on the way.
Wind Vanes
Even more ancient than the barometer, wind vanes explain something far simpler -- the direction of the wind. Like a blade of grass that blows in the wind, wind vanes operate in much the same way. They consist of a base, which holds the wind vane in place, as well as a horizontal bar -- resembling a bow and arrow -- attached to the vertical bar at the center-most point. The attachment point allows free rotation, meaning that whichever direction the wind is blowing, the arrow will point.
Campbell Stokes Recorder
Think you're a weather instrument expert? One lesser-known invention is the "Campbell Stokes Recorder," named after its creator. This instrument cleverly indicates the level of sunshine present throughout the day. It consists of a glass sphere, held at a 45 degree angle towards the sun. When the sun strikes the glass, the light is focused on a measuring card within the instrument. A burn mark caused by the light will show the levels of sunlight.
Sling Psychrometer
Another unusual weather instrument is the "sling psychrometer," designed to read humidity levels. It consists of a specialized thermometer attached to a handle. The ends of the thermometer have a wet and a dry bulb. To operate the psychrometer, grip the handle and spin the thermometer around. Readings of the intersecting point on the thermometer will give an idea as to humidity levels.