Hot water holding systems have been used as far back as the Romans. They particularly liked building hot water baths, of a communal nature. I would suspect that as soon as the copper and bronze age occurred, a shaped bowl was used to heat water.
Army Tanks
1911-The oxegen breather was invented. By:Dreager of German.
So you can use gravity rather then a pump to get water out of them.
rain water collected from roofs of houses,making tanks,etc.
hot air balloon
1884
No, they are rigid.
Yes, there is a website that lists used hot water tanks. You can get a list of them at www.energystar.gov/index.cfm?c=tax_credits.tx_index
the hot water temperature will not reduce due to atmosphere temperature.
To prevent the heat dissipating.
There is no way short of cutting it off. Hot water tanks are not made to be opened.
Most home electrical hot water tanks will hold 40 gallons.
What ever your hot water tank is set at -- must likely not more than 120 degrees I set hot water tanks at about 110 degrees
As long as you have the same model.
All major home improvement stores will have information on hot water tanks. Some of these are Homedepot, Lowes,Menards and Ace Hardware. Information can also be found at websites of these stores.
Air tanks were invented to hold compressed air.
The first functional battle tanks were invented in 1915