Unused double 20 amps breaker in my old 1 bedroom appartment?

[giotrader]

Hi I have a 1 bedroom appartment from 1954.
I opened my breaker box to find out what the extra double 20 amp was used for and I realized that it's disconnected.
15 amp goes for the lighting and the plug 120V outlets of the appartment.
20 amp the whole kitchen
double 20 amp is the hot water
40 amp is the oven
another double 20 amps disconnected, one loose wire isolated with marettes.
The heating is not part of the box as it's central for the building.
I do not have washer/dryer.
What could this unused double 20 amp could be? Is it something from the past that used to require 2X2X20amps? I am really scratching my head.

 

[kcanning]

What could this unused double 20 amp could be?

"What could this unused double 20 amp could be?"

^ In my situation a few short years ago, the two 20 amp breakers used to serve an electric hot water heater. When the heater was changed for a new natural gas one, the two breakers stayed in the panel box, albeit disconnected.