This really is two stories rather than one - a doomsday story, & an ET story. Both themes appear to be rather dear to Clarke's heart - going by number of stories he has written on these themes. Title comes from second story.
Story summary (spoiler).
Let's first talk about the second story - since title is named from this.
Assume an alien race from skies comes across a single photographic movie reel, without sound, from earth, & were to try reconstructing our life & culture? It is this speculation that essentially occupies the second half. E.g., is the orifice that often opens & closes in the lower half of the top round portion of these erect bipeds some kind of breathing device! That is a sample.
First story reminds me of the story of 108 tribes in the epic novel "Return of the Aryans" by B S Gidwani. Aryans obviously came after Clarke's story, but most of its stories are based on very old Indian literature & archaeological records. I don't really know the connection - except that two stories are nearly identical - in tone, theme, as well as presentation.
A tribe of humans is running from a disaster, crossing mountains on its move southwards - in search of new life. In Aryans, the tribe was running from famine & crossing Himalayas; in this story, tribe is running from advancing glacier, & crossing an unnamed mountain.
Now, lets fill in the blanks. For some reason, the Sun has cooled - without any other obvious effects. This has set Venus towards becoming friendly for intelligent life, & has doomed earth in a permanent ice cover.
First story is the about last days of humanity - glaciers are advancing from north & south - meeting mountains near tropics. While mountains the tribe is crossing are not named, you might be able to guess.
While earth is dying, Venus is in bloom. Thousands of years hence, Venus is dominated by an intelligent lifeform that is essentially reptilian. As they discover space travel, & come examining the third icy planet that could never have held life, they detect a faint radio signal. A kind of atomic powered beacon was secured up in a mountain cairn by the last tribe of humans as a sacred relic, along with a few other things - among them the photographic motion picture.
Second story is the attempt to interpret these relics & reconstruct the life as it was on earth - by Venusians.
Now the silly part. There is an echo of this Venus bloom in Clarke's more recent novel - "2010 Odyssey Two". Venus has cooled in former; Europa has heated up in later. In both cases, a life-friendly world has been created, & evolution moves at speeds way beyond anything witnessed on earthly evolution. There is another twist to Venus tale - in just 5000 years since bloom, not only are there conscious beings, but space farers comparable in competence to modern humans! In 2010, at least it took 20,000 years to reach the stage of stone age humans. Never mind that dumb earthly humans took something on the scale of billion years to achieve these feats!
- Earth turns into an icy wasteland at the end of "The Fountains of Paradise" also.
- An alien ship also visits a barren earth at the end of "The Ghost from the Grand Banks", & after much searching, is able to pick up a beacon that tells the story of intelligent life that once flourished here.
History Lesson, short story, review
Author: Arthur C Clarke
First published: 1949
Listed in Contento's Top Ten Most Reprinted Stories.