112 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
each succeeding century, so longas the ground was replanted after 
being cleared. But unless the trees were all growing under the 
same conditions in respect to soil and situation, those on the most 
favourable parts of the ground would arrive at maturity much 
earlier than their less favoured neighbours ; and in order, there- 
fore, to prevent the necessity of cutting before ripe, or causing a 
break in the returns, the ground should be classified into one, two, 
or three classes, according to its estimated capability of producing 
timber, or the length of time each class would require to bring 
timber to maturity, and a block in each class planted in the same 
year. Let the ground be supposed to consist of 500 acres of 
Class I., capable of bringing timber to maturity in 80 years ; 250 
acres of Class IT., requiring 120 years ; and 250 acres of Class III., 
requiring 150 years to mature its timber. By dividing Class I. 
into blocks of 12°5 acres each, and Classes II. and III. into blocks 
of 8-3 acres each, and planting a block in each class annually, we 
should have a continuous crop of mature timber from the 80th to 
the 180th year from the time planting commenced, the latter 
operation extending over a period of 33 years, about 30 acres 
being planted annually until the work was completed. Should 
the ground be at all exposed, planting should commence on the 
leeward side of it, and gradually worked up to the windward side, 
as by this method the removal of those blocks which require 
cutting first is effected without exposing the ones immediately 
adjoining them to the prevailing wind, and the tops of the trees 
present a uniform slope to the wind, and it is therefore less likely 
to do damage. 
The above system has the disadvantage of giving a plantation 
on a hill-side a patchy appearance, owing to the great difference 
in the sizes of the trees, but this would only be the case when the 
ground presented a great many variations of soil and exposure, as 
when planting proceeded steadily in one direction this would 
prevent such an appearance from being given to it. 
The formation of roads at the time of planting is quite 
unnecessary, besides adding greatly to the compound interest 
on the initial expenses. They should, however, be marked off, 
and the ground left unplanted, or if planted, such trees should be 
used as are likely to be of some value when the time comes for 
their removal. Narrow rides about 13 feet in width should 
separate all blocks from their neighbours, and should be kept free 
of grass and rubbish, as in case of fire they may prove of great 
