[Info-vax] Why is starting epoch 17 Nov 1858?

[David Jones]

On Thursday, March 11, 2021 at 12:44:07 PM UTC-5, Dave Froble wrote:
> > First, without looking it up, explain the what a BTU is.
> It's been a while, but I seem to recall it is the amount of heat 
> required to raise an amount, I forget the amount, of water one degree 
> Fahrenheit. I could look it up, but why bother. 

I believe it is  a pound of water.
> 
> What I do seem to have some feeling for is sizing furnaces, and how many 
> BTUs should be used for a specified area, say, 2000 sq ft. 
> 
> Oh, darn, there I go again, using those damn imperial measurements. The 
> thing is, I can function with them. I have no idea what 2000 sq ft 
> comes out to in millimeters, centimeters, meters, or whatever. 
> 
And then there is refrigeration/AC, which is traditionally rated in tons (how
many tons of ice per day it can produce). AC is rated by output, but gas
furnaces are rated by the nominal heat potential of the input.