FOREST UTILIZATION 85 



F. Manufacture of heading, staves, hoops and barrels. 

 I. Heading. 



Heading for tight cooperage is sawn from split bolts. 

 These bolts are obtained in the woods by halving, quar- 

 tering and splitting (by hand and always with the 

 grain) round blocks which slightly exceed in length 

 the diameter of the heading. The heart of the bolt is 

 not removed. The bolts are wagoned or sledded to the 

 heading plant, where they are inspected, sorted, piled 

 and air dried. 



Twenty-five horsepower are said to be required at a head- 

 ing plant. The output at a "setting" of the plant aver- 

 ages 200,000 sets of heading. 



The tight heading plant usually contains a sawing ma- 

 chine, an equalizer and jointer. 



(a) The heading sawing machine consists of a vertical 



circular saw (44 inches diameter) screwed to 

 the arbor without a loose collar; a pendulum 

 swing with "grate" and "dogs" to receive the 

 bolt; a slide guiding the swing; a gauge, ad- 

 justed by screws; a separator throwing the 

 sawed slats to the side. Price $300. 



(b) The- equalizer contains a tilting table or a carriage, 



which is forced against a pair of circular saws. 



(c) The jointer edges the slats. It consists of a strong 



wheel carrying on its side 4 to 6 straight knives. 



The wheel is covered by a hood. Price $140. 

 For tight cooperage the joints are made secure by 



blind wooden nails and by coopers' flag (Typha 



latifolia) glued into the joints. 

 Two more machines are required to finish the 



heading prepared by the apparatus mentioned 



under a, b. and c, viz. : 



(d) The heading planer carries knives 16 inches to 24 



inches wide and has a capacity of 8,500 headings 

 a day. 



(e) The heading turner cuts the heading circularly 

 and carves the required bevel edge. It usually 



carries a concave saw, to cut through the boards, 

 and on the same mandrel a small, thick circular 

 saw which gives the bevel. 



The heading, held in clamps, rotates obliquely 

 against these saws. Price $235. Capacity 5,000 

 a day. Heading is usually kiln dried. 



For slack heading, quarter sawing is usually not 

 required. Ordinary lumber can be used. The 

 slack heading plant may or may not contain all 

 of the machines enumerated under a, b, c, d 

 and e. 



