516 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



and lay a coat of copal varnish on one, and a coat of coal tar on 

 the other, the coal tar will penetrate the farthest. 



The Chairman said he saw it stated in a paper that in England 

 5,000 acres of timber was used yearly for sleepers and other 

 purposes on railways. 



Mr. Koch said it was universally conceded that the greatest 

 loss was occasioned by the sap. Extracting the sap, and con- 

 centrating the fibres of the wood, he thought was the cheapest 

 and most simple process that existed. He had been in the inte- 

 rior of California a good deal and found a great many trees 

 standing without any bark, perfectl}^ seasoned, and to all appear- 

 ance they would last two or three generations longer. It was 

 found nearly impossible t6 cut them down. Palm wood will last 

 nearly 150 years. 



Adjourned to Thursday evening, Nov. 15, 1860, at 1^ o'clock. 



American Institute, Polytechnic Association, ) 

 JYovember 15, 1860. ) 



Professor Mason in the chair. 



PRESERVATION OF WOOD. 



The Chairman inquired how long the sap was injurious to wood. 

 He stated that it had been ascertained that trees have lived from 

 5 to 700 years. It was stated that there are trees now standing 

 on Mount Lebanon which Avere there in the time of Solomon. 

 Trees are only useful after they are cut down, not having given 

 any return during their lifetime. What relation has the pith of 

 the tree every where diffused through the wood from the centre — 

 what relation has this to the preservation of the heart wood of 

 the tree ? Men and trees are nearly alike in their construction — 

 so much so that the sinews of a man resemble the heart wood of 

 a piece of hickory. The same agent which nature sets to work 

 to make them is set to work after vitality ceases to pull them 

 asunder. The first thing to be done towards preserving wood is 

 to keep out that destructive agent oxygen, and to drive out what 

 oxygen first takes hold of to commence its work of destruction. 

 A favorite pupil of the Chairman has become a railroad presi- 

 dent, and this was the man who invited him to bring this subject 

 before the meeting for the purpose of discussing the best mode 

 of preserving bridges and railroad ties. This young man has 

 reduced the cost of running an engine on that road from 89 to 59 

 cents per mile. 



