ves the depth in inches and parts of an inch.
In fixing these gauges, care must be taken that the rain may have free
access to them: hence the tops of buildings are usually the best
places. When the quantities of rain collected in them at different
places are compared, the instruments ought to be fixed at the same
heights above the ground at both places, because at different heights
the quantities are always different, even at the same place.

_To make beautiful Transparent coloured Water._

The following liquors, which are coloured, being mixed, produce
colours very different from their own. The yellow tincture of
saffron, and the red tincture of roses, when mixed, produce a green.
Blue tincture of violets, and brown spirit of sulphur, produce a
crimson. Red tincture of roses, and brown spirits of hartshorn, make a
blue. Blue tincture of violets, and blue solution of copper, give a
violet colour. Blue tincture of cyanus, and blue spirit of
sal-ammoniac coloured, make green. Blue solution of Hungarian vitriol,
and brown ley of potash, make yellow. Blue solution of Hungarian
vitriol, and red tincture of roses, make black; and blue tincture of
cyanus, and green solution of copper, produce red.

_Curious Experiment on Rays of Light._

That the rays of light flow in all directions from different bodies,
without interrupting one another, is plain from the following
experiment:--Make a little hole in a thin plate of metal, and set the
plate upright on a table, facing a row of lighted candles standing
near together; then place a sheet of paper or pasteboard at a little
distance from the other side of the plate; and the rays of all the
candles, flowing through the hole, will form as many specks of light
on the paper as there are candles before the plate; each speck as
distinct and large as if there were only one candle to cast one speck;
which shows that the rays do not obstruct each other in their motions,
although they all cross in the same hole.

_The Power of Water._

Let a strong small iron tube of twenty feet in height be inserted into
the bung-hole of a cask, and the aperture round so strongly closed,
that it shall be water-tight; pour water into the cask till it is
full, through the pipe; also continue filling the pipe till the cask
bursts, which will be when the water is within a foot of the top of
the tube. In this experiment the water, on bursting the vessel, will
fly about with considerable violence.