The existing refineries were accordingly altered so as to adapt them for the refining of petroleum; but in the manufacture of burning oil from petroleum the small stills which had been in use in the distillation of shale-oil were at first employed.
Of almost equal importance are the sugar refineries and chicory factories.
In the best-appointed refineries the whole of the work in connexion with the char is performed mechanically, with the exception of packing the filter cisterns with fresh char and emptying the spent and washed char on to the carrying bands.
In the American petroleum refineries it is found that sufficient cracking can be produced by slow distillation in stills of which the upper part is sufficiently cool to allow of the condensation of the vapours of the less volatile hydrocarbons, the condensed liquid thus falling back into the heated body of oil.
In most modern refineries the cisterns are so arranged that the spent char falls on to a travelling band and is conducted to an elevator which carries it up to the drying floor of the charcoal kiln.
Then follow the petroleum refineries and kindred industries, saw-mills and the fabrication of various wood articles, paper and milling.
A small pipe entering below the false bottom allows the air in the cistern to escape as it is displaced by the water or syrup. In some refineries this pipe, which is carried up to a higher level than the top of the cistern, is fitted with a whistle which sounds as long as the air escapes.
Brewing, distilling, cooperage, iron-founding, hatmaking and machine construction are carried on, and there are flour-mills, brick-works, saw-mills, sulphur refineries and leather and paper works.
Czechoslovakia manufactures and exports agricultural machinery, plant for sugar refineries and distilleries, locomotives, railway carriages and trucks and other rolling-stock, motor-cars, tractors.
When Cuba was the chief sugar-producing country making clayed sugars it was the custom (followed in refineries and found advantageous in general practice) to discharge the strike of crystallized sugar from the vacuum pan into a receiver heated below by steam, and to stir the mass for a certain time, and then distribute it into the moulds in which it was afterwards clayed.