The North Branch — it is all solid.

March 24.

Very pleasant day. Thermometer 48° at noon. 

9 A. M. -- Start to get two quarts of white maple sap and home at 11.30. One F. hyemalis in yard. Spend the forenoon on the river at the white maples. 

I hear a bluebird’s warble and a song sparrow’s chirp. So much partly for being out the whole forenoon. Bluebirds seen in all parts of the town to-day for first time, as I hear. The F. hyemalis has been seen two or three days. 

Cross the river behind Monroe’s. Go everywhere on the North Branch — it is all solid — and crust bears in the morning. Yet last year I paddled my boat to Fair Haven Pond on the 19th of March!

The snow is so coarse-grained and hard that you can hardly get up a handful to wash your hands with, except the dirty surface.  Before noon I slump two feet in the snow. 

The early aspen buds down very conspicuous, half an inch long; yet I detect no flow of sap. 

The white maple sap does not flow fast generally at first, —or 9 A. M., — not till about ten. You bore a little hole with your knife, and presently the wounded sap—wood begins to glisten with moisture, and anon a clear crystalline tear-like drop flows out and runs down the bark, or drops at once to the snow. This is the sap of which the far-famed maple sugar is made. That’s the sweet liquor which the Indians boiled a thousand years ago. 

My sugar-making was spoiled by putting in much soda instead of saleratus by accident. I suspect it would have made more sugar than the red did. It proved only brittle black candy. This sap flowed just about as fast as that of the red maple. It is said that a great deal of sap will run from the yellow birch. 

Cut a piece of Rhus Toxicodendron resting on rock at Egg Rock, five eighths of an inch in diameter, which had nineteen rings of annual growth. It is quite hard and stiff.

The river begins to open generally at the bends for ten or twenty rods, and I see the dark ice alternating with dark water there, while the rest of the river is still covered with snow.

H. D. Thoreau, Journal, March 24, 1856

I hear a bluebird’s warble . . . Bluebirds seen in all parts of the town to-day for first time, as I hear.  See   February 24, 1857 ("As I cross from the causeway to the hill, thinking of the bluebird, I that instant hear one's note from deep in the softened air. It is already 40°, and by noon is between 50° and 60°. As the day advances I hear more bluebirds and see their azure flakes settling on the fence-posts."); See also A Book of the Seasons, by Henry Thoreau, Signs of the Spring: Listening for the Bluebird

The F. hyemalis has been seen two or three days. See March 24, 1854 (“Great flocks of hyemalis drifting about with their jingling note.”); March 18, 1857 ("I hear the chill-lill or tchit-a-tchit of the slate-colored sparrow, and see it.”); March 19, 1858 ("Hear the pleasant chill-lill of the F. hyemalis, the first time have heard this note."); ; March 20, 1855 ("At my landing I hear the F. hyemalis”); March 20, 1852 ("And now, within a day or two, I have noticed the chubby slate-colored snowbird (Fringilla hyemalis?),. . . It has two white feathers in its tail."); March 23, 1852 ("Apparently they sing with us in the pleasantest days before they go northward.") See also A Book of the Seasons, by Henry Thoreau, The Dark-eyed Junco; andA Book of the Seasons, by Henry Thoreau, Signs of the Spring, the note of the dark-eyed junco going northward

The early aspen buds down very conspicuous, half an inch long See February 6, 1856 ("The down is just peeping out from some of the aspen buds."); February 27. 1852 ("The buds of the aspen show a part of their down or silky catkins."); March 4, 1860 ("Aspen down a quarter of an inch out."); March 18, 1854 ("The willow catkins this side M. Miles's five eighths of an inch long and show some red. Poplar catkins nearly as large, color somewhat like a gray rabbit");  March 21, 1855 ("Early willow and aspen catkins are very conspicuous now."); March 22, 1860 ("The phenomena of an average March . . .willow catkins become silvery, aspens downy"); March 25, 1856 ("The willow and aspen catkins have pushed out considerably since the 1st of February in warm places.")

March 24. See A Book of the Seasons, by Henry Thoreau, March 24