Tank steamers were constructed for the carriage of oil in bulk. Many of these ships were adapted not only for the carriage of oil, but also for its consumption in their furnaces in place of coal. The experience of many years has enabled the owners of some of these lines to exhibit a wonderfully low record of loss, the percentage of deaths at sea to numbers carried being small beyond the dreams of, say, the 1870s. A tenth of 1% over a somewhat extended period is not an unprecedented average.