An animation showing the relationship between pressure and volume when amount and temperature are held constant. Boyle's law (sometimes referred to as the BoyleâMariotte law, or Mariotte's law) is an experimental gas law that describes how the pressure of a gas tends to increase as the volume of the container decreases.
Multiple-alarm fire. One-alarm, two-alarm, three-alarm fires, are categories of fires indicating the level of response by local authorities, with an elevated number of alarms indicating an increased number of phone alarms went off during the fire. The term multiple-alarm is a quick way of indicating that a fire is severe and is difficult to contain.
Siren (alarm) A siren is a loud noise making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire trucks. There are two general types: pneumatic and electronic. Many fire sirens serve double duty as tornado or civil defense sirens, alerting an entire community of impending danger. Most fire sirens are either mounted on the roof of a fire station or on a pole next to