Reset Button. Most boilers have safety devices built in, so if these are tripped a simple reset may get your whole system working. The reset button is normally on the front of the boiler. Sometimes it's a dial that needs resetting to zero and turned back on.
A typical diffusion constant for a medium-sized molecule in water is about . If we want the smell to travel a quarter mile, or a little less than , we get a speed of. This speed is fantastically slow, and says that it would take ten million years for blood to diffuse out to a shark a quarter mile away.
Sharks hear sounds with frequencies ranging from 10Hz to 1KHz, and are especially responsive to sounds 500Hz or lower. In tests, the inventor found that sharks will not come within five feet of the noisy device, which if worn by swimmers, could protect them in the water (illustrated)