Drying of Timber. 67 



Owing to financial considerations, it has been found impossible 

 to publish all the graphs, but P'ig. 1 is typical of the series. In the 

 graphs for the first trees felled there was a tendency for the curves to 

 sink downwards in the sapwood area, but there was nothing definite, 

 however. When the first tree was felled, there was no sign of the burst- 

 ing of the buds. On the 23rd March, when the second tree was felled 

 some of the buds appeared as if they were commencing to swell, but 

 there was no further indication of bursting when the third tree was 

 felled on April 22nd. In the graphs for these three trees, the curves 

 rise steadily from the centre of the tree to the outer portion of the 

 heartwood, just as is the case in Fig. 1. 



The fourth tree was felled on June 2nd and the fifth on July 27th. 

 Both these trees were in full leaf, and transpiration was greatest. The 

 last tree was felled on September 1st. The oaks were still green, but 

 some of the other trees were showing signs of autumn. The lime 

 {Tilia Europoea) was well advanced with its autumn tints. The 

 graph for the last tree did not differ materially from that given. 

 Taking the graphs as a whole, it would appear that the moisture con- 

 tent of the heartwood is constant. There is, however, a well marked 

 rise from the centre to the sapwood. 



In Fig. 2 is given the moisture distribution of Scots Pine (Pinus 

 ■sylvestris) . The tree was a very fine specimen, and was growing in a 

 pure stand of pine. It was felled on February 25th. It will be seen 

 that the moisture content of the heartwood is very low as compared 

 with that of the sapwood. The difference between the moisture con- 

 tent of heartwood and sapwood cf oak is small. In pine, the mois- 

 ture content of the heartwood is very low as compared with that of 

 oak, while the content of the sapwood of the pine is much higher 

 than that of oak. A low moisture content of the heartwood appears 

 to be characteristic of conifers generally. The moisture distribution 

 is not only very low in the heartwood, but it is very evenly distri- 

 I)uted. There is no steady rise from the centre to the sapwood. The 

 vertical distribution is also very uniform. From the practical stand- 

 point, the heartwood of pine is easy to dry owing to the small 

 and even distribution of the moisture. 



In Fig. 3 are given the graphs of the moisture distribution of 

 several trees. With the exception of spruce, the sections were taken 

 at breast high. All these trees were growing in the same forest from 

 which the oaks were obtained. The spruce (Picea excelsa) was a 

 very fine specimen. It was felled on April 22nd, and the section was 

 taken just above ground level. The graph conforms to those of the 

 pine. There is the same low heartwood content and extremely high 

 sapwood content. The poplar (Populus nigra) was a fine tree, and 

 was felled on April 22nd. The distribution of the moisture was extra- 

 ordinary. 



The birch (Betula alha) was felled on March 25th. It also has a 

 peculiar moisture distribution. The holly {Ilex aquifolium) was felled 

 on August 5th. The graphs in Fig. 3 show that the lateral moisture 

 distributon in trees requires investigation. Such varying distribu- 

 tions of moisture may very seriously affect the drying of lumber, 



6a 



