798 7'kaxsactjons of the American Isstitute. 



An Acre— a Yaluablk Table. 



The Chairman read from a slip forwarded by a correspondent the 

 folloM-ing measurements, which indicate tlic area of an, acre of land : 



Five yards wide by 968 yards long ; 10 yards wide by 484 yards 

 long ; 20 yards wide by 242 yards long ; 40 yards wide by 121 yards 

 long ; 80 yards wide by 60f yards long ; 70 yards wide by 60| yards 

 long : 229 feet wide by 198 feetlong ; 440 feet wide by 99 feet long ; 

 110 feet wide by 369 feet long; 60 feet wide by 726 feet long ; 120 

 feet wide by 363 feet long ; 240 feet wide by 181^ feet long. 



Fexce Posts. 

 ' Mr. B. Roberts, East Varick, N. Y. — Please post me in the matter 

 of fence-posts. Will coal-tar preserve them \ "Will salt pickle them ? 

 Will blacksmiths' cinders save them ? Can you assure me of any 

 plan that will make " tlieir days long in the land V' Shall I interfere 

 with Providence and turn them tlie other end up ? 



Prof. H. E. Coltun. — If he will thoroughly season his posts and 

 soak them in hot resin oil, that will make them Very similar to tlie 

 " lightwood " posts we have at the south, and they last forever. 



Mr. Adrian Bergen. — Half the persons who put up fences do not 

 let their posts season. Two years is sliort enough time. A post put 

 up greeii will decay rapidly, no matter what is put on it. 



Horace Greeley. — If he will observe a little, he will see the sense 

 and reason why posts should be set top end down. The lower end 

 of a tree was created by nature to absorb moisture more freely than 

 higher up its body. If the top end is put downward, it will not 

 absorb as much water — it is repelled by the pores of the wood, and 

 will last one-third longer. 



Mr. II. L. Peade. — I remember a fence I once helped to put up, 

 and one-half the posts were set but end, the rest top end down. 

 After several years tlie whole fence was taken away, and we found 

 tliat one-half the posts were decayed, the rest sound. 



Prof. J. A. Whitney. — The decay of wood, as is well known, 

 arises from the fermentation or decomposition of albuminous matter 

 contained in it. This fermentation can only take place in the pres- 

 ence of moisture. The first step then is to dry the wood thoroughly 

 by seasoning, and afterward to keep it dry. I have read that there 

 are chestnut rafters in old English churches that, having been so 

 ))laced as to remain dry, have lasted for more than 800 years, and are 

 as sound to-day as when the Saxon workmen fitted them in their 



