Large tanks of boiler-plate are used to receive the oil as it comes through the pipe-lines.
This is easily done in liming or measuring tanks of known capacity, into which the juice is run from the mill.
In many gardens open-air tanks have been fitted up with hot-water pipes running through them to keep the water sufficiently warm in severe weather.
In districts where the water is of a " hard nature," that is, contains bicarbonate of lime in solution, the interior of the boiler cylinders, tanks and pipes of a hot water system will become incrusted with a deposit of lime which is gradually precipitated as the water is heated to boiling point.
With " very hard " water this deposit may require removal every three months; in London it is usual to clean out the boiler every six months and the cylinders and tanks at longer intervals.