A story tells that a senior villager led some other villagers carrying salt day and night to a town in order to trade rice as food the winter.One night they camped in a wilderness with a starry sky above.The senior villager,obeying the tradition passed down from forefathers,took out three blocks of salt and threw them into the campfire,probably to predict the changes of weather in the mountains.     All eagerly waited for the old man's"weather report":if the salt in the fire produced crackling sound,they would have good weather in store;if no sound was produced,it then meant the good weather would soon end and a storm would come at any moment.     The senior villager looked serious.The salt in the campfire made no sound at all.Convinced by this bad sign,he urged the whole team to set out immediately after daybreak.A young man in the group,however,insisted that they should not start in such a hurry,considering it superstitious to"forecast weather by using salt.     It was not until the next afternoon that the young man caught up on the wisdom of the old man when the weather suddenly changed,with cold winds blowing and a snowstorm raging.In fact,the method used by the clan head could be well explained by modem science:whether or not salt produces sound in campfire depends on air humidity .That is to say,when a storm approaches,due to high humidity,the dampened salt blocks will not produce any sound in fire. The weather reportthey got that night  _  .
had a bad sign gave wrong information was superstitious at that time was scientific according to modem science