Some recent posts dealt with whether people in the US know what an acre is, or rather how big it really is. It is probably true that few people know how many square feet are in an acre, but most owners of rural property have a pretty decent idea of just how many acres they own, and how much space on the ground an acre covers. If they look at a field they can often give a fairly accurate estimate of the area in old-time acres. This comes from walking around their own property and being familiar with the physical "feel" of the land. I have become fairly good at this because we used to own 2.5 acres and now own 20 (hilly ones out in the boondocks).
One small problem for us is that a hectare is about 2.5 times as large and therefore more difficult to get a feel for, I think. 100 m by 100 m is a pretty large bit of ground, especially if it is hilly and covered by trees or brush. With practice, one can estimate area in hectares as easily as in old-time acres, and I can certainly do it on flat ground because I know exactly what 100 m looks like (the length of a track straightaway at the high school). I wonder if there is anything else that we all encounter that is the size of a hectare, such as (possibly) a typical city block. I can't think of one right away. There was a well-reported bit on the BBC news yesterday about the brush fires in Sydney consuming xxx hectares with a front of yyy kilometers. HARRY WYETH
