With open-fire batteries for making the syrup, which was afterwards finished in the vacuum pan, very good sugar was produced, but at a cost that would be ruinous in to-day's markets.
An open fire acts by radiation; it warms the air in a room by first warming the walls, floor, ceiling and articles in the room, and these in turn warm the air.
Therefore in a room with an open fire the air is, as a rule, less heated than the walls.
range and from cover they were able to open fire on the Austrian gunners under conditions which renlered the case fire of the latter practically useless; but here was the opportunity a great cavalry leader on the Austrian side might have seized to restore the battle, for the ground, the shortness of the distance, and the smoke and excitement of the cannonade were all in favour of the charge.
Stoves were known, but most commonly heat was obtained from an open fire in the centre of the building.