xxxix.] PRODUCE AND WASTE. 335 



" Well-squared timber," as understood in the trade, 

 is nearly die square, and admits of little wane on the 

 angles at any part of the log. The yield of this is 

 about *68 per cubic foot of raw material, as shown in 

 the table against Tewart. Some woods, when exceed- 

 ingly well squared, will often yield a little more ; as 

 Mexican Mahogany. Others again, which are imper- 

 fectly manufactured, yield considerably less per cubic 

 foot ; as African. 



The figures against Oak, English, were obtained from 

 the conversion of both " rough " and " sided," not square 

 timber. Also the figures against Elm, English, were 

 obtained from " rough," and not square timber. 



The results given in the table were obtained from 

 the conversion of timber for ship-building at Woolwich 

 Dockyard. For civil architecture and engineering 

 purposes the yield per cubic foot would probably be 

 better, as there would be less waste in cutting to straight 

 than to curved lines. 



The advantage of the table will be manifest on trial, 

 since, if the figures in column A, which stand against 

 any one of the woods mentioned in the list, are used 

 as divisors of the net quantity of converted timber 

 material required for any purpose, the quantity of hewn 

 or square timber, i.e., raw material, which it is necessary 

 to purchase to produce it, is readily found. 



Example : If 5,600 cubic feet of converted timber 

 material (Dantzic Fir) are required, how much hewn 

 or square timber will it be necessary to purchase to 

 produce it ? 



In column A, against Dantzic Fir, is 700 ; therefore 

 f| = 8,000 cubic feet. 



Also, if the figures in column A are used as 

 multipliers, the converted produce can be ascertained 



