Edward Reinfeld, age 11 of San. Francisco, Calif.., far his question:

How long did the Ice Age last?

There have been several Ice Ages during the long history of the earth, The first one about which we know occurred soma 500 million years ago, when the most advanced form of life was soft little blobs living in the ooze of shallow seas.

The other Ice Age occurred in the Permian Period, some 200 million years ago. By this time the backboned animals had established themselves on the land. There were amphibians and primitive reptiles. There ware giant dragonflies, dense forests of conifers and giant ferns. The glaciers of this Ice Age were in a broad belt around the equator. They covered parts of India., Africa, Australia and South America,

We find traces of these early ice Ages in the rocks of the earth’s crust. But the evidence is so old and worn that it is hard to set an exact t3.m or estimate how lox they lasted. We can, however, be more precise about the more recent Ice ,leas, though even here the experts are still debating about how long they lasted.

 It is no easy matter to put a date on some event which happened thousands of years before re‑corded history begin ~‑ according to latest information, the last Ice Age finally loosened its grip on Minnesota about 15,000 years ago. This last Ice Age was one of a series of four which invaded the northern states of America during the past two million years.

We name‑: each one for a state which felt the cruel grip of the glaciers.

Two million years ago Canada and. the northern birders of the United States were under the terrible glaciers of the Nebraskan Ice Age. After hundreds, perhaps thousands, of years the glaciers retreated to polar regions and the world enjoyed a long, long period of warm weather.

Then came the glaciers of the Kansan Ice Ages which followed almost the same path.  North America was under the mighty weight of its ice sheets about one and a quarter million years .ago These glaciers, too, relented and withdrew and there was another long warm period.

The glaciers of the Illinoisan Ice Ago did not come quite so far south. Canada New England, the Great Lakes area and the borders of our northern states were under these ice sheets about half a million years ago, Again this icy period was followed by a very long warm period.

We do not know exactly when the Wisconsin glaciers began to creep southward, but we do know that these last Ice Age glaciers took hundreds and perhaps thousands of years in their journey, about 40,000 years ago the southern edges of the ice sheets began to melt. The Niagara Falls region was freed about 36,000 years ago and New England 28,000 years ago. For the past 15,000 years we have enjoyed the warmer climate which has followed each of the last four wintery Ice Ages.