For a good many years past the construction of oil tankers has been one of the important branches of industry in the leading shipbuilding countries; and they carry not only the predominating American product, but that of all the scattered oil fields of the world. They bring crude to our seaboard refineries, but they carry little crude away; their business is that of conveying the finished oils to other lands. The shipment of the crude product of American wells overseas has long since ceased as a result of the stupendous development of our refining industry, but Mexico has lately come into prominence as an exporter of crude. In comparison with the earlier oil ships the modern tanker shows the same ratio of growth which characterizes all phases of petroleum development. The place of the tiny craft of the ’sixties and ’seventies has been taken to-day by the tanker which runs to dimensions of more than 500 feet in length and correspondingly wide beam. Whereas the little Belgian ship, the _Charles_, fifty years ago carried a maximum of 295,000 gallons, one of the larger types of modern oil tankers will carry more than 4,500,000 gallons. The greater petroleum organizations do not depend on private shipping firms to carry their products, but build their own vessels. The great American tankers of to-day are equipped with ample deck space so that the officers and sailors have more freedom of movement than do many city-dwellers in their own home. The impulse that the petroleum industry has given to the American merchant marine as a whole is developing a seafaring spirit among American youths that was non-existent a generation ago. Many of the American tankers are among the largest that fly the Stars and Stripes. Such giant vessels coming up the fairway of a foreign port constitute a graphic advertisement for the United States, and serve as the symbol of an industrial nation standing at the head of the world’s commerce. It is fitting that the American flag should have been carried to every port of the seven seas in connection with petroleum, the American product which has revolutionized the world’s industry. These great vessels carry the source of light, heat and industrial energy to peoples of every language and every colour. Great progress has been made in economizing time and labour in connection with cargoes. Where but a few years ago it required days to load or unload a ten-thousand ton ship, the task is now performed in a few hours. The oil is handled by the use of powerful pumps or by gravity, when possible. Owing to the speed with which oil cargoes are handled no other ships on the ocean do so much sailing, or spend so little time in port as the oil tanker.