The mechanical department is under the general supervision of the superintendent, but in direct charge of a mechanical-electrical engineer. This man is known as the chief engineer, and he is directly responsible, not only for the operation of all the machinery in the plant together with its upkeep and repair, but he has also to cope with engineering problems that are constantly arising. Under his direction, a corps of draughtsmen is always busily engaged in planning and designing improvements and additions. He also maintains a force of mechanics, watching, operating and repairing the machinery. These men represent almost every trade, including machinists, blacksmiths, coppersmiths, tinsmiths, millwrights, boilermakers, riggers, masons, painters and many others. The diversity of the mechanical work around a refinery is remarkable, and the engineer in charge must be a man of exceptional mechanical ability, as his duties include not only steam, electrical and civil engineering, but construction engineering of an advanced character. As refineries are always built on sites bordering on deep water, harbor engineering problems are also constantly before him. In connection with every refinery there are many shops, where mechanical work incidental to repairs and construction is carried on. These shops are equipped with the necessary tools and implements for quick repairs and are under the supervision of the chief engineer. In addition, there is the cooper shop where many thousands of barrels are turned out daily, and the bag factory where twenty cotton bags and twenty burlap bags must be made for each and every ton of output packed in that manner. The mechanical department of a modern refinery is as important as it is extensive, for failure in any one of its branches means costly delays. The machinery is run twenty-four hours each day, except Sundays, during about eleven months in the year. The plant is closed down the remaining thirty days for annual cleaning and repairs. Intelligence and ability, tempered with good judgment, bring about the _esprit de corps_ that gives the necessary results. The mechanical is almost as important as the chemical department and, as before stated, it is subject to the general supervision of the chemical engineer. [Illustration: LABORATORY] [Illustration: OIL-BURNING BOILER PLANT] LABORATORY The chemical laboratory is really the heart of the institution, for upon it depends the success of every manufacturing operation. The superintendent of a refinery must possess a thorough knowledge of chemical engineering, for the process of sugar refining is largely chemical from beginning to end.