94 FOREST UTILIZATION 



III. The splitting machine severs, by the gradual strokes of a 



knife (first stroke down to l /2, second stroke down to 

 Y of thickness of disc), the disc into strips of pegs and, 

 playing crosswise, into individual pegs. After each 

 stroke of the knife the disc is moved toward it by the 

 width of one furrow. During the operation the disc 

 is held in a leather frame. 



IV. The wet, red pegs are then bleached by applying sulphuric 



acid ; then dried in heated drums ; then cleaned from 

 splinters and irregularities by sifting. 



XXX. EXCELSIOR MILL. 



A. Grades of product. 



First Grade Fine wood wool, thickness from 1/500 inch to 



1/64 inch. 



Second Grade Common fine wood wool. 

 Third Grade Mattress stock. 



The greatest demand is for stock i/ioo inch thick and 

 from 1/32 to 1/8 inch wide. 



B. Usage. Excelsior is used for upholstering and for packing (glass- 



ware, furniture, confectionery etc.). It is preferred to straw 

 - owing to its greater elasticity and to its lack of dust. -It is easily 

 colored. A limited amount of excelsior is woven into mattings 

 and rugs. 



C. Kinds of wood. 



Basswood is best ; balm of gilead, cottonwood and yellow poplar 

 come next. Pine and spruce also are used. One cord of wood 

 will yield 1,500 pounds of excelsior. 



D. Process of preparation. 



The wood is peeled, cut into 38-inch blocks, and the blocks split 

 into slabs 5 inches to 6 inches thick. These slabs are thoroughly 

 air seasoned under cover, and finally cut into two lengths of 

 18 inches each. 



Frequently the core of blocks peeled on the rotary veneer machine 

 is used for excelsior. 



E. Machinery. 



Excelsior machines are small, upright knife machines, or carry 

 the knives on a disc set in rapid rotation. The modern machine, 

 however, is an eight block horizontal machine consisting of: 

 I. Two sliding steel frames carrying eight tool heads into 

 which the knives and the comb-like spurs are spanned. 

 The sliding frames are moved by powerful cranks and 

 pitmans on maple slides. 



II. Two stationary frames, above the sliding frames, each 

 having four sets of rolls, each set pressing a block by 

 its rotation downward against the knives. 



III. ' The shavings, falling through the sliding frame, are car- 

 ried out by broad belts. 



