Eugene Bouchard, age 13, of Littleton, Mass., for the questions

How wide is the equator north and south?

We learn that the equator is a line around the wide waist of the world. Pleasure cruisers often make a great to‑do about crossing this line on the ocean. Any passenger who owns up to the fact that this is his first crossing may be put through ceremonies such as walking the plank and other merry goings‑on. All this gives us the idea that the equator is a wide, clearly marked band around the middle of the earth ‑ while actually it is no such thing.

Nature never put an equator for on the earth ‑ we did. And it is not market with a white highway line or any other line because, for one thing, most of it crosses the ocean. The only points of reference which nature put on the earth are the north and south poles. These are the opposite ends of the axis on which the earth turns. The equator and all our lines of latitude and longitude are based on these two natural points of reference.

The equator is the halfway mark between the two poles. Every spot on earth which is exactly halfway between the two poles is at the equator, Since the earth is a globe$ these halfway spots arrange themselves in a line around the middle. A navigator has to use his instruments very carefully to know when ho is exactly at the: equator. He can stay on the equator by standing still or moving directly east or west. If he moves the slightest distance north he is then north of the equator. If he moves a stop south ha is then south of the equator.

Soy you seep the equator has no northern or southern boundary. It is merely an imaginary line, a manmade point of reference in charting the face of the globe. From it we chart the parallel lines of latitude which circle the earth.. The equator itself is Latitude 0 degrees,

Between the equator and the North, pole there are 90 parallel lines of latitude and the north pole itself is Latitude 90 degrees north of the equator. Between the equator and the south pole there are also 90 equally spaced parallels and the south pole is Latitude 90 degrees south of the equator. The parallel lines of Latitude are about 69 miles apart and each keeps the same number clear around the earth:

The lines of longitude run from pole to pole and intersect the equator at right angles. Here too the lines, or degrees, are about 69 miles apart. But the lines of longitude taper closer together until they finally meet at the poles. Lines of longitude change their numbers at the poles. Longitude I degree, for example, runs from the north pole through Greenwich, England down the Atlantic to the South Polo. On the opposite side of the globe from pole to pole it is longitude 186 degrees.