the principle is best explained by giving an example. the author was concerned in the development of a continuous process for an aerated boiled sugar bar which has been made for many years on the batch principle. the basic process was relatively simple merely the addition of sodium bicarbonate to a high boiled syrup, stirring well and tipping the magma on to tables to cool and mature after which it was cut into bars. the original process produced small batches and slabs which has to be cut, and that which was not the right thickness was wasted and had to be reclaimed by an expensive decolorizing and filtration process.