Part 24 (1/2)

_Another curious Experiment with Oil and Water._

Drop a small quant.i.ty of oil into water agitated by the wind; it will immediately spread itself with surprising swiftness upon the surface, and the oil, though scarcely more than a tea-spoonful, will produce an instant calm over a s.p.a.ce several yards square. It should be done on the windward side of the pond or river, and you will observe it extend to the size of nearly half an acre, making it appear as smooth as a looking-gla.s.s. One remarkable circ.u.mstance in this experiment is the sudden, wide, and forcible spreading of a drop of oil on the surface of the water; for if a drop of oil be put upon a highly polished marble table, or a looking-gla.s.s, laid horizontally, the drop remains in its place, spreading very little, but when dropped on water it spreads instantly many feet round, becoming so thin as to produce the prismatic colours for a considerable s.p.a.ce, and beyond them so much thinner as to be invisible, except in its effect in smoothing the waves at a much greater distance. It seems as if a repulsion of its particles took place as soon as it touched the water, and so strong as to act on other bodies swimming on the surface, as straw, leaves, chips, &c., forcing them to recede every way from the drop, as from a centre, leaving a large clear s.p.a.ce.

_Remarkable Effects on the visual Nerves, by looking through differently-coloured Gla.s.ses._

After looking through green spectacles, the white paper of a book will, on first taking them off, appear to have a blush of red; and after looking through red gla.s.ses, a greenish cast. This seems to intimate a relation between green and red, not yet explained.

_Weather Table._

--------------------+---------------------+------------------------ NEW AND FULL MOON.

SUMMER.

WINTER.

--------------------+---------------------+------------------------ If the new or full

moon enters into

the first or last

quarter of the

hour of 12 at noon

Very rainy

Snow and rain.

If between the

hours of

(P.M.) 2 and 4

Changeable

Fair and mild.

4 and 6

Fair

Fair.

6 and 8

{ Fair, if wind

{ Fair and frosty, if

{ at N.W.

{ wind at N. or N.E.

{ Rainy, if wind

{ Rain or snow, if S.

{ at S. or S.W.

{ or S.W.

8 and 10

Ditto

Ditto.

10

Fair

Fair and frosty.

(A.M.) 2

Ditto

{ Hard frost, unless

{ wind S.S.W.

2 and 4

Cold, with frequent

showers