Now let me clear the palate with a tale of mystery and fuses. We stepped outside and saw the filter in the pond wasn't working. Also the garage door wouldn't open. We checked the circuit breaker but couldn't find any breaking to be done to the (detached) garage. The door is a real problem as there's not a release in the event of power failure, so the only way in when that breaks is to pry open the garage's window, which of course the painters painted closed. So, we had to cut the paint out and pry the window open, where we got the garage door open, and found that the fuse box (a) exists and (b) had apparently blown its two fuses. There were two little 15-Amp fuses of the kind that look like the base of incandescent bulbs there, with the strips gone. There was also a 30-Amp fuse resting on the floor in the middle of the garage, as if it had dropped from the heavens.
We got replacement fuses, which took two hardware stores to find, because the one that's actually near us never has anything, and at both of which the clerks said they haven't seen the all-glass fuses like we had in years. We put in the new fuses and none of the outlets in the garage worked. But, also important, we tried extension cords from the house's outlets and by process of elimination found that the extension cord from the garage to the power plug we used for the filter wasn't working, though the filter was.
The next day, 
bunny_hugger's parents came over to replace the outdoor socket which needed a new ground fault interruptor anyway, and they brought out a power tester to verify when the new socket was off or on. Her mother pointed out we could test the fuse box for power, and yeah, power was flowing through it. Also, somehow, one of the sockets which wasn't working the day before. Something apparently had popped the GFCI units on all the sockets and while we thought we'd reset them, either we failed to, or something popped them again, possibly the lightning storm that rolled through that night. In our defense, the buttons for this are really slender things, flush against the sockets, and are easy to mis-read.
The extension cord, too, we found out why it broke, and have a tentative exlanation for the fuse box and GFCI problems: something had chewed it open. There was a spot with all the rubber gone and some of the insulation torn out. Fortunately it had only chewed so far as to the ground wire, which we imagine is why there wasn't a dead animal beside the chewed-up wire.
And so, the mystery: where did that 30-Amp fuse come from, that appeared in the middle of our garage floor? Note that our fuse box takes 15-Amp fuses.
My best explanation: I found a bit of a dusty ring on top of the fuse box that's about the right shape for the interior lettering ring on the 30-Amp Sears fuse. As to why someone with a 15-Amp fuse box would have a 30-Amp fuse kept on it, well, this fuse box also has dust-covered pennies sitting atop it, so ...
Long story short: our garage has not since burned down, and we have enough spare fuses to keep us supplied for decades to come.
Trivia: Bushrod Washington served on the United States Supreme Court from 1798 to 1829. (If I'm not overlooking something he was the latest-serving justice appointed in the 18th century.) Source: The New York Public Library Desk Reference,Editors Paul Fargis, Sheree Bykofsky.
Currently Reading: The Science Of Fear: Why We Fear The Things We Shouldn't --- And Put Ourselves In Greater Danger, Daniel Gardner.