The convexity of the earth.

August 11. 

This morning the river is an inch and a half higher, or within eight inches of the top of Hoar's wall.

The other evening, returning down the river, I think I detected the convexity of the earth within a short distance. I saw the western landscape and horizon, reflected in the water fifty rods behind me, all lit up with the reflected sky, though it was a narrow picture. A stroke of my oar and the dark intervening water was interposed like a dark, opaque wall. Moving my head a few inches up or down produced the same effect; i.e., by raising my head three inches I could partially oversee the plane of the water at that point, which was otherwise concealed by the slightest convexity.

P. M. — Walk to Conantum with Mr. Bradford. 

He gives me a sprig of Cassia Marilandica, wild senna, found by Minot Pratt just below Leighton's by the road side. How long? P. thought it in prime August 10th.

Aster puniceus a day or more. 

A new sunflower at Wheeler's Bank, this side Corner Spring, which I will call the tall rough sunflower; opened say August 1st (?). (I saw it out the 7th.) It does not correspond exactly to any described. Stem three to six feet high, branched at top, purple with a bloom, roughish, especially the peduncles. Leaves opposite, except a few small ones amid the branches, thick , ovate or ovate-lanceolate, taper-pointed, three-nerved, obscurely and remotely toothed, rough above, smooth and whitish below, abruptly contracted into margined petioles. Scales of the involucre lanceolate, taper-pointed, subequal, exceeding the disk,ciliate; rays eight or nine, one and a half or more inches long, chaff black. Edge of meadow.

Measured a mulgedium, eight feet three inches long and hollow all the way. 

Some boy had fixed an arch-angelica stem so as to conduct the water at the spring close by. 

Elder-berries in a day or two. 

I see some Hypericum angulosum turned a delicate clear purple. 

Polygonum dumetorum at Bittern Cliff, one flower gone to seed (!); say day or two.

7 p. m. — The river has risen about two inches to day, and is now within six inches of the top of Hoar's wall.

H. D. Thoreau, Journal, August 11, 1856


I think I detected the convexity of the earth. . . by raising my head three inches. See June 7, 1851 ("You may walk out in any direction over the earth's surface, lifting your horizon, and everywhere your path, climbing the convexity of the globe, leads you between heaven and earth.”) See also Samuel Birley Rowbotham ("If the earth is a globe, and is 25,000 English statute miles in circumference, the surface of all standing water must have a certain degree of convexity—every part must be an arc of a circle. From the summit of any such arc there will exist a curvature or declination of 8 inches in the first statute mile. In the second mile the fall will be 32 inches; in the third mile, 72 inches, or 6 feet." ~ wikepedia)

Elder-berries in a day or two. See August 9, 1854 ("'Walden' published. Elder-berries.")

Hypericum angulosum turned a delicate clear purple.  See July 25, 1856 ("Up river to see hypericums out.”); July 26, 1856 ("Arranged the hypericums in bottles this morning and watched their opening. The H. angulosum has a pod one-celled (with three parietal placentae), conical, oblong, acute, at length longer than the sepals, purple.”) See also A Book of the Seasons,  by Henry Thoreau, St. Johns-wort (Hypericum)

August 11.  See A Book of the Seasons, by Henry Thoreau, August 11

 

A Book of the Seasons,  by Henry Thoreau

"A book, each page written in its own season,

out-of-doors, in its own locality.”

~edited, assembled and rewritten by zphx © 2009-2021