tapping ; that the theory that all or nearly all of the sap comes 

 from the outer wood is erroneous, and that our sugar makers 

 may with great profit, tap their trees to a depth of four or five 

 inches. The additional injury to the tree is slight, especially if 

 the hole is small and the bark but slightly hewn away. Where 

 a }i inch bit is used and the bark practically uninjured by hew- 

 ing, a majority of the holes will be grown over the first summer 

 after tapping. If double the amount of sap can be obtained by 

 tapping four inches deep, instead of two, and the sap be of nearly 

 equal richness, then it is time to stop giving directions to tap 

 but one inch deep as many have done on the assumption that 

 the sap from the inner wood was scanty and poor. 



In 1892 two trees with as uniform tops as could be found and 

 standing in thick woodland, were tapped both on the north and 

 south sides. A similar tree was tapped on the south and west 

 sides. With trees 6 and 20, the south side yielded about 23 

 per cent, more than the north side, while with tree 12, the west 

 side exceeded the south side by about 9 per cent. It is of in- 

 terest in connection to depth of tapping to note that tree 6 was 

 tapped i}4 inch deep, and trees 12 and 20, 2}( inches deep. 

 All with }4 inch holes. Table 4 gives the results in detail. 



TABLE 4.— FLOW OF SAP FROM NORTH AND SOUTH SIDES OF TREES. 



A few observations made in 1893 and 1894 are in accord 

 with the results from trees 6 and 20. Without doubt differences 

 in season and the exposure of the trees to the sun have much 

 to do with the results from tapping on difi^erent sides of the 



