Very early in the spring, often as early as March, the sap begins to flow up through the tree. The farmer knows by experience when to tap the tree, which he does by boring a three-quarter inch hole with an auger. Into this hole he inserts a spout of wood or iron through which the lifeblood of the tree—the sap—flows in a steady drip, drip, drip, into a pail or bucket placed beneath to catch it.
The sap comes in drops about as regularly as the ticks of a clock, one a second. This continues for two or three weeks, until each tree has yielded something like twenty-five gallons. As it takes five gallons of sap to produce a pound of sugar, each tree yields about five pounds of maple sugar. In New England and New York there are maple groves containing thousands of trees, and one farm alone produces five thousand pounds of sugar in a season.
Strange as it may seem, this excessive bleeding of the trees does not kill them unless improperly done. The farmer must not tap them at the wrong time nor in too many places. The tree will stand a great deal if properly treated, but harsh treatment will kill it.
The boiling process is very simple. The sap is poured into large boilers or evaporators and boiled until it becomes a sirup. The old-fashioned test to find out when the boiling had been carried on long enough was to drop a little of the hot sirup into the snow or into a cold dish. If it hardened, the boiling was finished.
[Fig. 90] shows the leaf of the sugar maple, also that leaf which is most often confounded with it, viz., the Norway maple. Observe the two closely. The sugar maple has blunt, rounded points and is thick, while the Norway has sharp points, which are more numerous, and the leaf is much thinner and more delicate.
Fig. 90.
Sugar Maple Norway Maple
The sugar maple grows taller and does not cast so dense a shade as the Norway, which is a low-growing tree with close, dark foliage.