=542 ON USEFUL AND BOOK I. 



at the bottom than at the top. By this means, every part has 

 " the full advantage of the sun, air, and rain : it grows equally 

 thick throughout, and particularly below, where it is most ne- 

 cessary. But when a hedge is trained broader at top, or even 

 perpendicular, that half of it nearest the ground is under the 

 drip of the rest; and, deprived of sun and rain, it sickens, pro- 

 duces few or no young shoots — the sap is attracted to the top 

 of the hedge — it becomes quite bare below ; and is soon unfit 

 for a fence. Every accurate observer will allow that this is the 

 case, more or less, in the greater part of what are generally con- 

 sidered as the best kept hedges, such as those that surround 

 the market gardens in the neighbourhood of London and Edin- 

 burgh, which, though they are annually cleaned and shorn with 

 great care v are commonly so naked below, as to give easy ac- 

 cess to hares, dogs, swine, &c. In pruning a hedge, the bill 

 or knife should be used, as being preferable to the shears. The 

 latter bruise off, rather than cut over, the twigs ; and hence, 

 every shorn hedge throws out a great number of small shoots 

 from this surface of bruised twigs, which in time forms a kind 

 of coating or net-work all over the hedge, inclosing the naked 

 stems within, and by excluding the air from them ruins the 

 hedge. But the knife cuts off the twigs clean and smooth. 

 By this means, they throw out fewer shoots, but those are of 

 greater strength ; and the hedge is equally thick in every part, 

 without being crowded. This excellent mode of pruning hedges 



