@michigan-left?ÿ As I understand it, to claim those expenses you have to have detailed logs to support the percentage claimed if any of it is shared....

January 1970 inside the back of some magazine like Popular Mechanics?

That was 1959. Alaska in January, Hawaii in August. So a lot of us qualify. I even remember it happening.

My favorite science communicator notes that it's a milestone for net energy within the reaction but it really isn't net energy for the overall process...

Some sort of level vial?

I think NAD83 was fully complete in 1986.?ÿ That's the way it goes.

Sealed Lead Acid and AGM batteries hold up better than ordinary ca/motorcycle batteries.

Maybe call it midpoint?

The statistically best value is the arithmetic mean (average) of the three readings. There are several ways to express the disagreement of the measur...

I don't know, but will guess that it's a 3 1/2" tripod head with the remains of a target holder screwed on it. ?ÿ