312 REPORT OF THE COMMISSIONERS OF 



While it is easy to understand why the mild weather of early spring should warm 

 the ground and start the flow of sap, it is not so clear as to how the cold nights can 

 possibly assist in such a result. The freezing seems to be incidental, rather than 

 necessary, to the process; especially, as the cold at this season is seldom severe 

 enough to freeze the wood to any depth, or have any effect other than to clog the 

 spouts with frozen sap. 



Although the sap rises in our forest trees* at all seasons of the year, except when 

 the wood is chilled by a low temperature, no outward flow of any large amount can be 

 obtained while the trees are in leaf. Maple sap will flow during any warm, thawing 

 day in winter, and Dr. Hough states that he has made sugar in each of the winter 

 months. But trees may be killed by winter tapping, for the bark is liable to loosen 

 through the action of the frost. In a pile of cordwood the sap will exude freely from 

 the ends of the maple sticks under the influence of the sun or warm, spring weather, 

 although the trees may have been cut in fall or midwinter. 



Trees differ greatly in the amount of sap which they produce. In favorable 

 weather an average tree will yield from two to three gallons in twenty-four hours. 

 One of ordinary size will discharge during a good season about twenty-five gallons of 

 sap; sometimes more, and sometimes less. 



Of course, there are phenomenal trees and phenomenal yields. Many years ago a 

 writer in the Greensburg (Pa.) Gazette stated that by inserting twenty tubes in a 

 hard maple tree he obtained in one day twenty-three and three-quarter gallons of 

 sap ; and that thirty-tree pounds of sugar were made from this tree during the season, 

 an amount which would indicate that it yielded over one hundred gallons of sap.f 

 Another record mentions a tree (in Massachusetts), six feet in diameter, which 

 produced a barrel of sap in twenty-four hours; and another which flowed 175 gallons 

 during the season. f Another writer tells of a maple which was tapped with ten 

 spouts, from which fifty pounds of sugar were made; but it killed the tree.|| 

 Dr. Hough, of Lowville, N. Y., kept a record on his own premises from 1877 to 1884, 

 which showed that the trees averaged nineteen gallons each season. This included one 

 poor season, 1883, in which the trees produced only one-fourth their usual amount. 



Maples standing on high ground, or uneven, rocky land, or on the hill sides, are 

 generally the best producers. Trees growing near cold springs yield sap in large 

 quantities, which is also rich in sugar of the best quality. Second-growth maple land 

 and young groves are also in good repute among the sugar makers. 





* The birch contains more sap than the maple. 



t Michaux. North American Sylva. Vol. I, p. 106. 



t Emerson. Trees and Shrubs of Massachusetts. Vol. II, p. 563. 



|| Garden and Forest. Vol. VI, p. 174. 



