the time of the sap hovers about the vernal equinox, beginning a week or ten days before, and continuing a week or ten days after.  As the days and nights get equal, the heat and cold get equal, and the sap mounts.  A day that brings the bees out of the hive will bring the sap out of the maple-tree.  It is the fruit of the equal marriage of the sun and the frost.  When the frost is all out of the ground, and all the snow gone from its surface, the flow stops.  The thermometer must not rise above 38 deg. or 40 deg. by day, or sink below 24 deg. or 25 deg. at night, with wind in the northwest; a relaxing south wind, and the run is over for the present.  Sugar weather is crisp weather.  How the tin buckets glisten in the gray woods; how the robins laugh; how the nuthatches call; how lightly the thin blue smoke rises among the trees!  The squirrels are out of their dens; the migrating water-fowls are streaming northward; the sheep and cattle look wistfully toward the bare fields; the tide of the season, in fact, is just beginning to rise.

Sap-letting does not seem to be an exhaustive process to the trees, as the trees of a sugar-bush appear to be as thrifty and as long-lived as other trees.  They come to have a maternal, large-waisted look, from the wounds of the axe or the auger, and that is about all.

In my sugar-making days, the sap was carried to the boiling-place in pails by the aid of a neck-yoke and stored in hogsheads, and boiled or evaporated in immense kettles or caldrons set in huge stone arches; now, the hogshead goes to the trees hauled upon a sled by a team, and the sap is evaporated in broad, shallow, sheet-iron pans,—­a great saving of fuel and of labor.

Many a farmer sits up all night boiling his sap, when the run has been an extra good one, and a lonely vigil he has of it amid the silent trees and beside his wild hearth.  If he has a sap-house, as is now so common, he may make himself fairly comfortable; and if a companion, he may have a good time or a glorious wake.

Maple sugar in its perfection is rarely seen, perhaps never seen, in the market.  When made in large quantities and indifferently, it is dark and coarse; but when made in small quantities—­that is, quickly from the first run of sap and properly treated—­it has a wild delicacy of flavor that no other sweet can match.  What you smell in freshly cut maple-wood, or taste in the blossom of the tree, is in it.  It is then, indeed, the distilled essence of the tree.  Made into syrup, it is white and clear as clover-honey; and crystallized into sugar, it is as pure as the wax.  The way to attain this result is to evaporate the sap under cover in an enameled kettle; when reduced about twelve times, allow it to settle half a day or more; then clarify with milk or the white of an egg.  The product is virgin syrup, or sugar worthy the table of the gods.