In article om, "Lee
Michaels" says...

"Robatoy" wrote

I never could figure out outhouses with two holes... what...take a
dump with a buddy? Wha?

For you city folks, who don't have much experience in outhouse design and
implementation, it may seem a mystery.

But as a country boy, who had to dig and build outhouses from time to time,
there is a practical consideration. It has to do with volume. If enough
people use one hole, you will fill up the ground hole and make the whole
outhouse experience extremely uncomfortable. By going to two holes, you get
a more even distribution of, cough, cough, well, you know.

Back in the day, they just used to drag the outhouse to a new hole/location
when one started to fill up. But when folks (and livestock) started to fall
in to the old holes, somebody came up with the two hole design. By the way,
I have seen three and four hole designs.

And for the real classy outhouses in snow country, they have styrofoam
seats. Much warmer on the behind when using the facility sitting down in
sub zero weather.

According to Nevada Barr, the Park Service just keeps the seat next to
the heater, and whoever needs to use it takes it out and brings it back.