A. Lightning sometimes passes _from the clouds_ to the earth, and sometimes _from the earth_ to the clouds; and therefore, the _middle story_ of a house is always the safest to be in, during a thunder-storm. Q. _When does lightning pass FROM THE EARTH to the CLOUDS?_ A. When the clouds are in a "negative" state of electricity. Q. _When does lightning pass FROM THE CLOUDS to the EARTH?_ A. When the clouds are in a "positive" state of electricity. Q. _What is meant by the clouds being in a "positive state of electricity?"_ A. When the clouds contain _more_ electric fluid than they _generally_ do, they are said to be in a _positive_ state of electricity. Q. _What is meant by the clouds being in a "negative state of electricity?"_ A. When the clouds contain _less_ electric fluid than they _ought_ to do, they are said to be in a _negative_ state of electricity. Q. _Does the flash proceed from a negative or positive body?_ A. Always from a _positive_ body, or one over-burdened with electric fluid. Q. _When lightning flashes from the earth to the clouds, what is the flash called?_ A. It is called the "returning stroke;" because the earth (being over-burdened with electric fluid) _returns_ the surplus quantity to the clouds. Q. _Why is it DANGEROUS to lean BACK AGAINST A WALL during a thunder-storm?_ A. Because the electric fluid sometimes runs down the _wall_ of a house or room; and (as a man is a better conductor than a brick wall), would make _him_ its path, and injure him. Q. _Why is it dangerous to RING a BELL during a thunder-storm?_ A. Bell-wire is an _excellent conductor_; and (if a person were to touch the bell-handle), the electric fluid, passing down the wire, might run through his hand and injure it. Q. _Why would the lightning run through a man touching a bell-handle?_ A. Because the human body is a better conductor than the _wall_ (between the bell-handle and the floor); and as lightning always chooses the _best_ conductors for its path, it would (in this case) pass through the _man_, and injure him. Q. _Why is it DANGEROUS to BAR a SHUTTER during a thunder-storm?_ A. The iron shutter-bar is an _excellent conductor_; and (if a person were touching the bar), the electric fluid passing down it, might run from the bar _through the person touching it_, and injure him. Q. _Why is it dangerous to be in a CROWD during a thunder-storm?_ A. For two reasons. 1st--Because a _mass_ of people form a _better conductor_ than an individual: and 2ndly--The _vapour_ from a crowd _increases the danger_ of such a place. Q. _Why is a MASS of bodies a better conductor than a single body?_ A. _Each_ living body is a _conductor of electricity_; and a connected _mass_ of such conductors is more likely to be struck, than a _single individual_. Q. _Why is the danger increased by the_ VAPOUR _which rises from a crowd?_