Papuan Timbers. 25 



In the first case, " heart shake " of a very pronounced 

 character is nearly always developed, in the second case " star," 

 and to a certain extent " cup shal^e " occurs, but in matured 

 wood the pith has generally begun to decay and the moisture is 

 being evaporated both from the inside and the outside, and if 

 seasoning checks do occur, they are in the form of small cracks, 

 which close up when the process is complete. Also, it is almost 

 a rule that the heavy dense woods contain the least moisture 

 and the more open grained and lighter ones contain the most. 



In these experiments, the dry weight of the several species 

 was obtained by weighing one hundred grains of borings, taken 

 from near the fracture, immediately after the specimen had 

 been tested. The borings were then placed in an oven, which 

 was kept for forty-eight hours and upwards, at a temperature 

 of 103 deg. C, kept there in fact until the weight ceased to 

 decrease. The loss of weight was thus directly found, and the 

 percentage of moisture accurate!}^ ascertained. Having obtained 

 the percentage of moisture in the timber, and having previously 

 ascertained the weight per cubic foot, it was easy to calculate 

 the ■" dry weight." 



That timber " comes and goes." or expands and shrinks with 

 the weather, can be verified during wet and dry seasons, when 

 many instances come under casual observation ; hence the ex- 

 pulsion of moisture decreases the weight of timber, and such 

 weight varies with the proportion of moisture it contains. In 

 the following table (Table 1) the percentage of moisture re- 

 absorbed was ascertained after allowing the dry borings, 

 already mentioned, to stand in the atmosphere for at least 

 seven days. During that time the thermometer never rose 

 above 73 deg. F., but the hygroscopic state of the atmosphere 

 varied. The results prove that timber, air dried, always con- 

 tains a certain amount of moisture, so that naturally-seasoned 

 timber must always contain moisture, and kiln-dried wood 

 will take up moisture until it reabsorbs within two per cent, of 

 the naturally seasoned wood. The fourth column in the table 

 will therefore give the limit, which the degree of moisture in 

 naturally-seasoned timber of these varieties may be expected 

 to attain in practice. 



