PENCIL, a name applied to instru ments for writing, drawing, or painting, differing as much in their construction as in the use to which they are applied. There are now in use the following kinds of pencils: Hair pencils, black lead pen cils, chalk pencils, and slate pencils. The first are used for painting or writ ing with fluid colors, either oil or water, and in China and Japan are employed almost entirely instead of pens for writ ing; the color used being the black or brown pigment obtained from various species of sepia or cuttle fish. The well known black lead pencil is made by cut ting black lead or plumbago. Some pen cils are filled with colored chalk instead of black lead.
The ever-pointed pencil is an instru ment for using cylindrical pieces of black lead, which are forced forward in the pencil just so far as to allow them to be used without breaking. The pencils for using liquid colors or paints are made of hog's bristles, camel's hair, fitch, sable, etc. Those of a large and com mon kind are described under BRush (q. v.). The soft pencils for artists are made as follows: The tail of the animal (sable, badger, marten, etc.) is scoured in a solution of alum; then steeped for several hours in lukewarm water; then dried in linen cloths; and finally combed out regularly. The hairs are seized with
pincers, and cut off near the skin, and the little parcels of hair are sorted into groups according to their length. A few hairs are then taken—enough for one pencil—and placed in a little receptacle, which holds them while a thread is bound round near the roots. The base of the pencil is then trimmed flat by scissors. The hairs thus prepared are fitted either into quills or into tin tubes. The quills are those of swans, geese, ducks, lap wings, pigeons, or larks, according to the size of the pencil. Each quill is softened and swelled in hot water; and the bunch of hairs is introduced at the larger end, and pulled forward by a simple appa ratus to the smaller end, where the shrinking of the quill binds the hairs closely. Women are generally more suc cessful than men in preparing the small and delicate pencils. Slate pencils, for writing on slate, are made either by cut ting slate into thin sticks, and rounding them, or by cutting it into fine square slips, and incasing them in wood, as in the case of black lead, etc.
In optics, an aggregate or collection of rays of light which converge to, or di verge from, the same point.