Rensselaer Republican, Volume 12, Number 50, Rensselaer, Jasper County, 3 September 1880 — How Slate Pencils are Made. [ARTICLE]

How Slate Pencils are Made.

Broken slate fiom the quarries is put into a mortar run by steam, and pounded into small particles. Thence it goes into the hopper of a mill, which runs it into a bolting machine, such as is need in flooring mills, where it is bolted, the fine almost impalpable floor that results being takes into a mixing tub, where a small quantity of steatite flour, manufactured in a similar manner, is added, and the whole is then made into a stiff dough. This dough is thoroughly kneaded by passing it several times between iron rollers. Thence it is carried to a table where it is made into chargee—that is short cylinders, four or five inches thick, and containing from eight to ten pounds each. Four of these arc placed in a strong iron chamber or retort, with a changeable nozzle, so as to regulate the size of the pencil, and subjected to t remendoos hydraulic pressure under which the composition is pushed through the nozzle in a long cord like a slender snake sliding oat of a hole, and passes over 1 a sloping table slit at right angles with the cords to give passage to a knife which cuts them into lengths. They are then laid on boards to dry, and after a few hoars are removed to sheets of corrugated zinc, tha corrugations serving to prevent the pencils from warping daring the process of baking, to which they are next subjected in a kiln, into which super-heated steam is introduced in pipes, the temperature being regulated according to the requirements of the articles exposed to its influence. From the kiln articles go to the finishing and packingroom, where the ends are thrust for a second under rapidly-revolving emery wheels, and withdrawn neatly and smooth ly pointed ready for use. They are then packed in pasteboard boxes, each contain ing 100 pencils; and these boxes in turn are packed for shipment in wooden boxes containing 100 each, or 10,000, pencils in s shipping box, Nearly all the work is done by hoys, and the cost, therefore, is light.