I may be perpetuating an "urban science legend", but i do recall that before
the turn of the last century, some large public spaces (ie theaters,etc) were
cooled by piling tons aof ice in theater lofts and blowing air across this as
it melted down into the audience spaces. Early mechanical refrigeration
systems were marketed as being able to do the same job as melting "x" tons of
ice in a 24 hr period. so a "1 ton" unit was the equvalent of melting a ton of
ice per day.
Jim Goff
JGOFF@PIMACC.PIMA.EDU