NOTES AND QUERIES. 



233 



Wood : Its Botanical and Technical Aspect. 



A lecture with the above title was delivered by Professor 

 Wm. Somerville, M.A,, D.Sc, at the Royal Institution, London, 

 on 20th February. The lecture was illustrated by a series of 

 diagrams of wood and of tables showing comparative growths 

 of different species of timber-trees. 



The Cost of Fencing. 



In connection with the subject of outlay on afforestation, one 

 often reads or hears that planting costs so much per acre, and 

 that some additional named sum, or some proportion of the 

 planting charge, must be added to provide for fencing. Persons 

 who give such rates doubtless quote from their own experience 

 in fencing particular tracts, where the cost was actually as 

 stated. But it is evident that such figures, however accurate 

 they may be, cannot be generally applied, all fencing estimates 

 given in the form of a constant rate per acre, or in that of a 

 constant proportion to the planting charge, being fallacious. 



The cost per acre of planting is not much affected by an 

 increase or a decrease of the area stocked. If a contractor be 

 employed, he charges a rate per acre which does not greatly 

 vary with the area. But the cost of fencing works out very 

 differently, as may be seen from what follows. Assuming the 

 side of a square plot of ground covering one acre to be 70 yards, 

 the length of a fence enclosing it will be (4 x 70) 280 yards, and 

 the cost at is. a yard will be ^^14 — that is, ^14 per acre. 

 Take a second square plot covering 4 acres, and it is clear 

 that while the area has been increased four-fold, the length of 

 the fence has only been doubled. And if the calculation be 

 carried a little further, we arrive at the following results : — 



VOL. XXI. PART II. 



