How fires will be extinguished in the skyscrapers of the future, according to the March 1927 issue of Science and Invention magazine.
Not wanting to bother to do the math, but the pressure in that vertical line must be extremely high. Figure a 5" line going up 26-odd stories (so about 260 feet). Plus the supporting "helicopter" would have to be able to support that weight as well; 8 pounds per gallon *plus* the weight of the hose.
I need sleep.