Frightening off thunder demons
Man has always had a wholesome respect for thunder and the destructive power of lightning. Age-old evidence of this fear is to be found in the extent to which "thunder-magic" enters into the religious traditions and folk lore of primitive peoples. Indeed, it is not surprising that thunder was often given the status of a god in many ancient cultures.
To the Norsemen, for example, lightning was caused by a fierce and red-headed god called Thor, who hurled to earth his magic hammer, Mjollner, from a goat-drawn chariot rolling across the thunder-clouds of heaven. The clouds themselves, it was believed, were a mixture of water with an inflammable vapour called a vafermest; when the cloud was split by Thor with his magic hammer, the two were separated - one falling as rain, the other catching fire and descending earthwards as a bolt of lightning.
In medieval times, the accepted wisdom was that thunderstorms were caused by dark spirits in the air. By frightening away these demons with a loud noise, the worst of the tribulations might be avoided - and what better way to create a din than to sound the bells of the local church as loud as possible?
So orthodox did this practice become, in fact, that Pope Urban II in 1091 authorised a special prayer for use by bishops when they consecrated bells: "Grant 0 Lord, that the sound of this bell may drive away harmful storms, hail, and strong winds, and that the evil spirits that dwell in the air may by Thy almighty power be struck to the ground". And the bells themselves were often inscribed Fulgura Frango - "I breakup the lightning".
Nothing alas, is that simple in this world and human nature frustrated these attempts to harness devine acoustic intervention. Firstly, many people living some distance from the bells believed that the noise diverted thunderstorms in their direction, and they were understandably annoyed. And a serious problem was the number of bell-ringers who were killed by lightning; church towers were particularly vulnerable to lightning-strikes.
At the other extreme, some villages complained that they were being unfairly treated by the authorities, because they had no bells to ring.
Such was the extent of all these difficulties that at one point Charlemagne was obliged to issue an edict forbiddinq the use of church bells for this purpose. But then communities who suffered frequent lightning strikes complained that they were being deprived of the right of self-defence; many defied the edict, even to the extent of overpowering the unfortunate pastors who tried to enforce their emperor's dictum.