The aim of the Watching series is to draw attention to some of the very interesting items around us, things that perhaps we don't notice as much as we might. The first was Bridge Watching, and when this was put ''on the Net'' it produced, to the surprise of the author, such a pleasant flood of e-mail that another was written, called Water Watching. This, too, was kindly received. So it was tempting to continue with the theme. Many people know very little about bells, and some, sadly, know nothing at all. This is a pity for, large or little, they can be engaging objects. You might think that ''Bell Hearing'' might be a better title; but looking at bells has its own attraction, too. In England, church bells are well known, because of the sounds they make, though many people have not seen the bells themselves. Doorbells, too, are familiar items in many houses, but are rarely regarded with any particular interest. Some of these are not what is popularly imagined as bell-shaped, and are more properly chimes. Then there are bicycle bells, cowbells, and many other kinds, too, all well worth a thought. Things that are free are doubly attractive. It costs nothing to enjoy the pleasures of getting to know these interesting objects. Learning a little about the fascinating qualities of bells in general can be an enjoyable occupation, and can start a lively curiosity about them. The more you know about them, the more interesting they become.