If an ABC puts out all 3 fire types, why would you ever get a BC extinguisher that doesn't put out type A fires? Why even sell BC extinguishers? What am I missing?
In 1902 George Andrew Darby, an electrical engineer of 211 Bloomsbury Street, Birmingham, England, patented the electrical Heat-Indicator and Fire Alarm. The device was a heat alarm rather than a smoke detector and indicated an increase temperature in the apartment where it was fixed. The device operated by closing an electrical circuit to sound an alarm if the temperature rose above the safe limit. The contact was made by bridging a gap with a conductor, or allowing one plate to fall on another. The connection of the two plates was caused simply by a block of butter which melted as the temperature rose. This early device subsequently gave way to more modern fire and eventually smoke alarms. In 1969, two Americans, Kenneth House and Randolph Smith patented the modern smoke detector
How deep? I'll mountain bike in up to a few inches, but more than that and it's too much resistance. On the road the tires just push through to pavement, but watch out for icy conditions. (You can get studded ice tires, but they're pricey). Lower your tire pressure for better traction. If you're made of money you can buy the Surly Pugsly, which has 4 inch wide tires. You can ride on sand or snow with that thing.
