“路不拾遗,夜不闭户”是古人的理想。然而,门闩、门锁久传不衰,证明在许多时候,不拒绝夜不闭户理想的人们,也不肯放弃每晚关门闭户,换得一觉到天亮的安全感。这中间,理想同现实相隔多远,如果要量一量的话,可借宋代《芝田录》之语当尺子:“门钥必以鱼者,取其不瞑目守夜之义”。这反映了一种颇为可爱的想法,夜须闭户,且要门扇上锁;那锁钥形状仿 “Road do not pick up the night, the night is not closed,” is the ancients ideal. However, the locks and locks have not been declining for a long time, proving that in many occasions people will not refuse the people who do not want to close the door at night, nor will they give up their night-time door-to-door feeling of security. In the middle, the ideal is far away from the reality. If we want to measure the quantity, we can use the language of “Zhida” in the Song Dynasty as a ruler: “The key to the fish is to take the unspoken meaning of vigil.” This reflects a rather lovely idea that night must be closed and the door locked; the key shape imitation