Lynn Brick, age 11, of Calgary, Alberta, Canada, for her question:

Why is pound abbreviated to lb.?

The first languages belonged to the people who invented them. But people tend to roam and even when they have to leave their bulky belongings at home, they take their native words with them. People also like to swap and trade their belongings. They frequently adopted words from new lands and from visiting strangers. But often they ended up with two names for the same thing. A mix up of this sort occurred long ago to the ancestor of our modern pound weight.

The conquering Romans imposed their Latin language on most of Europe. In those days, however, the weights and measures were not very precise and neither were their nays. Somehow two Latin words became confused. One was the ancestor of our word pound, the other was libra, which originally meant a pair of scales. The word pound survived to name our more precise unit of weight. An osld English word was substituted for the balance scales. But libra survived as lb., the abbreviated form for the pound weight.