In some localities the value of standing timber is made out by a surveyor who has specialised in this class of work. His calculations are based on the apparent cubical coutents of the trees growing over a given area; and their exactness will necessarily depend on the experience he has previously gained. But sight measurement can seldom be relied upon. The only satisfactory method of estimating, and the one most often followed, is to measure the timber height and girth of each tree on the plot separately. In such cases the trees are numbered, and the survey is conducted as here indicated: -

1898 Cutting. Treffgarne Hall Woods. Woodmoor Section

The first thing to ascertain is the price per foot each kind will realise when delivered at the place of sale. The price to be paid for the standing timber will then be found after the following items have been deducted - 1, cost of survey; 2, cost of felling; 3, cost of cartage, or rail, to market; 4, construction of temporary roads, or gaps through fences, and making same good; 5, extras to additional labour, etc., on account of difficult nature of ground: 6, profit. Firewood, if included, is to some extent a recoup on the above, but it is usually sold under separate agreement.