Although there are many intricacies involved in the measurement of timber, the cabinet-maker has little to do with any of them. The stuff he uses, and in such quantities as he is likely to buy it, is principally quoted for and sold at a rate per foot super. If the thickness is not specified this may generally be understood to mean I inch, but as a rule it is stated. Thus, in quotation a price will be given for any wood 1/4, 1/2, 3/4, or I inch, as the case may be, so that the purchaser can have no difficulty in knowing the exact cost of material. It should be noted that 1/2 inch stuff must not be regarded as costing only half the price of 1- inch, for the sawing must be taken into account. For this reason the thinner the stuff the higher its price per foot proportionately to that in the inch. The cabinet-maker seldom needs anything thicker than this, unless in the form of squares for legs, which in places where there is any considerable demand for them are often sold at so much each, per foot run, or per set of four, according to circumstances. When they are not, there is no difficulty in ascertaining their cost either from quotations or by estimating their contents of 1 - inch stuff, the price of which will approximately be known.
As the way of calculating superficial measurement may have been forgotten since their schooldays by those whose business does not necessitate its use, the following hints may be of use. The foot super contains 144 ins; therefore, to get at the superficial contents of any piece of wood, reduce the measurement of length and breadth to inches, multiply them together, and divide by 144. Thus, a piece 6 ft. 3 ins. x 1 ft. iin.= 75 ins. x 13 ins., these figures multiplied together give 975 ins., which divided by 144 give 6 ft. and 111/144th of a foot, or a little more than 9 ins. Another method of reckoning, and a less cumbersome one, is to proceed as follows: -
As boards do not always run of the same width throughout their length, it is usual to take about the average width. Of course, this does not apply to stuff of which the edges have been trimmed.
When the thickness of any wood is specified it must not be expected to measure the full. Thus, any one ordering stuff will find that it is almost invariably thinner than its nominal thickness. This is owing to the waste caused in sawing, for of course the saw removes a perceptible amount in its course instead of splitting through like a wedge. Thus, supposing a plank 3 ins. thick is to be sawn into boards 1 in. thick, there will be the width of two cuts or kerfs made by the saw to be deducted from the thickness of the three boards. As the stuff is only rough when it is sawn, the thickness will be further reduced by the necessary operations of smoothing it down. Thus, nominal 1 - inch stuff will probably not measure more than about 3/4 - inch thick down or finished. A proper comprehension of this fact will save many mistakes when setting out work, and it should not be forgotten. The actual difference between nominal and actual thickness varies, but it always exists to an appreciable extent, especially by the time the wood is planed down. Roughly, it may be said to vary from 1/8in. to 1/4 in.
It may be remarked that the quality and amount of figure in wood when rough cannot be easily determined without considerable experience, so that, to the novice, good and bad will look very much alike till part of the surface is cleaned up. It will not do therefore for him to rely much on his own judgment, but rather on that of a respectable dealer. Those who want wood in very small quantities can generally get it from a manufacturer of furniture; and here I would say that many of those who call themselves so do not make anything, but buy everything ready made. It is no use applying to such manufacturers (?) for stuff.
The importance of using only thoroughly seasoned dry stuff cannot be too strongly impressed on the cabinetmaker, and I have heard many amateurs complain that they cannot get wood fit to use. They have bought stuff which has been said to be well-seasoned, and yet when they have used it they have found that it has shrunk, split, or gone wrong in some way or other, leaving them with the fixed idea that they have been imposed upon. Now a few hints may be useful to those who have had such experiences, and prevent others from finding the same fault.
Timber, it must be understood, may be seasoned and yet not be dry enough for immediate use. If it is not dry, it will shrink in becoming so. Moisture or damp causes it to swell, the removal of the damp causes shrinkage, and unless this is unrestrained and even, the wood will probably split. When, therefore, wood fresh from an open timberyard, or from a cold storeroom not artificially heated, is worked up immediately in a warm, dry room, or the article made is kept in one, there is no wonder that it shrinks, or some part of it 'goes.' To those who know anything about it, the wonder would be if it did not. All stuff, even if it is 'seasoned,' should be kept in a warm, dry place for a time before it is made up. The stuff may not be wet or even damp to the touch, probably it is not, but all the same it can hardly be considered dry, from a cabinet-maker's point of view, if it has been stored in a cold place subject to every change of weather.
It is an exceedingly difficult matter to tell when wood is really dry and therefore usable, for whatever precautions are taken to ensure its being so, it really seems sometimes to be of no avail. Every now and then a piece of wood, which to all intents and purposes seemed as seasoned and dry as it could be, will, after months or even years, shrink and split. Few who have had much experience with furniture but could tell strange tales, almost incredible to the general public, about the vagaries of wood. The only thing the cabinetmaker can do is to have it as dry as possible before using it; and it must not be forgotten that wood always contains a certain amount of moisture. It may be only small, but it is there nevertheless, and, practically, it is impossible to get rid of it altogether. If the wood is made absolutely dry by artificial means it will absorb moisture from the atmosphere; hence it is impossible to keep wood perfectly dry.