separated from them with a very slight blow.
In Orkney, hailstones have fallen as finely polished as marbles, of a
greyish white colour, not unlike fragments of light-coloured marble.
Hailstones are often so hard and elastic, that those which fall on the
stones rebound without breaking to the height of several yards; and they
have been known to be projected from a cloud almost horizontally, and
with such velocity as to pierce glass windows with a clear round hole.

On the 7th May, 1822, some remarkable hailstones fell at Bonn, on the
Rhine. Their general size was about an inch and a half in diameter, and
their weight 300 grains. When picked up whole, which was not always the
case, their general outline was elliptical, with a white, or nearly
opaque spot in the centre, about which were arranged concentric layers,
increasing in transparency to the outside. Some of them exhibited a
beautiful star-like and fibrous arrangement, the result of rows of air
bubbles dispersed in different radii. The figures at the head of this
chapter show the external and internal appearances of these hailstones.

The smaller figures represent pyramidal hail, common in France, and
occasionally in Great Britain.

Brown hailstones have been noticed. Humboldt saw hail fall of the colour
of blood.

On the 15th July, 1808, Howard noticed, in Gloucestershire, hailstones
from three to nine inches in circumference; appearing like fragments of a
vast plate of ice which had been broken in its descent to the earth.

On the 4th June, 1814, Dr. Crookshank noticed, in North America,
hailstones of from thirteen to fifteen inches in circumference. They
seemed to consist of numerous smaller stones fused together.

On the 24th July, 1818, during a storm in Orkney, Mr. Neill picked up
hailstones weighing from four ounces to nearly half a pound.

[Picture: Rain gauges]

CHAPTER V.

METHOD OF MEASURING THE QUANTITY OF RAIN THAT FALLS--THE RAIN
GAUGE--METHODS OF OBSERVING FOR RAIN AND SNOW--EFFECTS OF ELEVATION ON
THE QUANTITY OF RAIN--DIFFERENCE BETWEEN THE TOP OF A TALL BUILDING AND
THE SUMMIT OF A MOUNTAIN--SIZE OF DROPS OF RAIN--VELOCITY OF THEIR
FALL--QUANTITY OF RAIN IN DIFFERENT LATITUDES--EXTRAORDINARY FALLS OF
RAIN--REMARKS ON THE RAIN OF THIS COUNTRY--INFLUENCE OF THE MOON--ABSENCE
OF RAIN--REMARKABLE DROUGHT IN SOUTH AMERICA--ITS TERRIBLE EFFECTS AND
CONSEQUENCES--ARTIFICIAL RAINS.

The quantity of rain w