Q. Why does a thunder-storm generally follow very dry weather, and rarely succeeds continued wet?
A. The clouds are always charged with electricity; but dry air (being a non-conductor), will not conduct the surplus fluid from the clouds to the earth: so it violently rends the dry air with a flash, in order to relieve the cloud, and reach the earth.
Q. What is the general direction of a thunder-storm?
A. Either from east to west; or else from north to south.
Q. Why is electricity excited by friction?
A. Electricity, like heat, exists in all matter; but is often in a latent state: friction disturbs it, and brings it into active operation. (see p. [31].)
Q. Why is a tree sometimes scorched by lightning, as if it had been set on fire?
A. Lightning scorches it by its own positive heat, just the same as fire would.
Q. Why is the bark of a tree often ripped quite off by a flash of lightning?