Rods and Rod Material. 207 



That rod material should be thoroughly dry when 

 made up is, therefore, very important. Absolutely dry 

 wood cannot be had. Destruction sets in before all 

 moisture is expelled. Wood dried as far as it will dry 

 at a temperature of 120 F. will still lose moisture if 

 raised to the temperature of 200 F. Thoroughly dried 

 under cover in the open air, wood still contains about 

 twelve per cent, of moisture ; in a dwelling-house, arti- 

 ficially warmed, from eight to ten per cent. Wood may 

 be further dried at a temperature not exceeding 120 F. 

 without injury. An inch stick takes twice as long to 

 reach a given dryness as a half-inch stick. 



So far the lesson is plain. We are to cut our sticks 

 as small as possible, dry them gradually to prevent sea- 

 son cracks, first air-drying them outdoors, then in a 

 warm place indoors, and finally, if we can find a good 

 hot place, giving them some days of that. 



But wood absorbs moisture from the atmosphere even 

 on the driest of days. Dry it with all care, and then 

 allow it to lie about at ordinary temperatures, and it 

 will begin to absorb moisture and deteriorate rapidly 

 at first, more slowly afterwards. Also, as far as strength 

 is concerned, it makes no difference whether the wood 

 is green or whether it has been dried in the best man- 

 ner and afterwards allowed to become moist. The cell 

 walls are equally softened and weakened in either 

 case. 



Again, the lesson is plain. After finishing a joint, 

 except, perhaps, the very last touch in fitting the fer- 

 rules, we are to give it another dose of the hot place 

 and varnish it as speedily as possible after removal 

 therefrom. 



Two or more points from the same source deserve 



