Septaria
ovate flattened nodules of argillaceous limestone or ironstone, internally divided into numerous angular fragments by reticulating fissures which radiate from the center to the circumcomponent parts of emulsions or suspen-ference, and are filled with some mineral sions, especially to the apparatus used in the separation of cream from milk.
All these machines work by centrifugal action. The simplest form consists of a number of buckets (usually two or four) suspended around a central shaft which can be caused to revolve at high speed by means of gears turned either by hand or by machinery. As the buckets revolve, they assume a horizontal position, the heavier portion of the mixture being forced to the bottom. Modern machines consist of a bowl or drum, frequently consubstance, as carbonate of lime or sulphate of barytes, that has been infiltrated subsequent to their formation. The radiating figure and the striking contrast between the dark body of argillaceous limestone or ironstone and the more or less transparent sparry veins when the nodule is cut and polished have caused them to be manufactured into small tables and similar objects.
Calcareous septarian nodules are extensively employed in the manufacture of what is known commercially as Roman SEPTEMBER cement, because of its properties being the same as a famous hydraulic cement made of ferruginous volcanic ash brought from Rome. Such septaria occur in layers in clay deposits, and are quarried layers 1 for economical purposes in the clays of the London basin.
The septarian nodules of the Carboniferous strata consist generally of clay ironstone, and are sometimes employed in the manufacture of iron.
SEPTEMBER (from the Latin septem, seven), the ninth month of our year, but the seventh of the old Roman year, which began in March. It has always contained 30 days.