Wood, when it is cut into small pieces, very soon acquires its utmost degree of dryness. Dr. Watson, Bishop of Llandaff, in the month of March, cut a piece from the middle of a large ash tree that had been felled about six weeks, and weighed it; its weight was 317 grains. In seven days it lost 62 grains, or nearly one-fifth of its weight. It was weighed again in August of the same year, but had not lost any more of its weight; hence it had become perfectly dry in the short space of seven days. He also found that the sap-wood of oak lost more weight in drying than the heart-wood, in the proportion of 10 to 7. The time that is required to season or dry a piece of timber obviously depends upon its magnitude; as a _general rule_, large timbers will not continue good so long as small ones, as sufficient time is rarely given for a thorough seasoning. The time required to dry a piece of timber, all other things being alike, will depend on the quantity of surface exposed to the action of the air; therefore, while the quantity of timber remains the same, the larger the surface, the sooner it will dry. Also, if the quantity of surface remains the same, the time of drying will be proportioned to the quantity of matter; as the greater the quantity of matter under the same surface, the longer it will be in drying. As drying proceeds most rapidly in small pieces, it is therefore important to reduce the timber to its proper scantlings or size for use; for however dry a piece of timber may be, when it is cut to a smaller scantling it will shrink and lose weight, being always less dry in the centre than at the surface; and the more rapidly the drying has been carried on, the greater will be the difference. Nevertheless, in the first stage of seasoning it is best that it should proceed slowly; otherwise, the external pores shrink so close as not to permit the full evaporation of the internal moisture, and the piece would split from unequal shrinking; and lastly, it should be reduced to the proper scantling, as already observed, some time before it is to be framed. Various tables have been given by writers on timber, the result of algebraical calculations, of the times of seasoning and drying for different woods of different lengths, breadths, and thicknesses, in the open air; but as wood even of the same description and quality varies so much, this matter is best left to those who are well acquainted with timber. It may, however, be stated that the time required for drying under cover is shorter than in the open air, in the proportion of 5 to 7.