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.
There exists a dubious record of a small Blue Shark about two feet in length which was found to swim steadily against a current at 17.7 mph and was reported to achieve 43 mph in short bursts. The most reliable record of a Blue Shark at speed is 24.5 mph for a 6.5-foot-long individual.