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.
Some newer sirens are electronically driven by speakers, though these are not as common. Fire sirens are often called fire whistles, fire alarms, or fire horns.. Although there is no standard signaling of fire sirens, some utilize codes to inform firefighters of the location of the fire.