Film: 9807

Science | 1950 | Sound | Colour

Clip:

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Synopsis:

A film, with a lot of speeded-up footage of beautiful cloud formations, that describes how cloud formation takes place and current experimentation to induce rainfall and reduce damaging hailstone storms.

A flock of wood pigeons against the sky. A gamekeeper with his gun walks by some oaks on a field edge. Close up, a spider's web in the grass, jangling slightly. Close up, same. Big close up, droplets of mist on the spider's web, on individual strands form an abstract pattern.

Front titles.

Fluffy white clouds in a blue sky. A white cloud passes a wooden church steeple and clock tower, seen from below. Big close up, a drop of condensation forms on a spider's web. Two drops of condensation or nuclei on a web, dry and turn into crystal formations. An archway of cliff at the end of an empty beach, possibly Fecamp in Normandy, with large banks of cloud. A large wave forms at sea and runs towards camera, breaking on rocks. A sea mist in the light as the sea breaks in foam on a pebble beach. Two children silhouetted against the clouds on the top of the beach. A view of the beach from the cliff top with cliffs, the arch, a rock needle and shadows of the clouds on the sea.

Aerial shot, flying towards a bank of clouds over a rural landscape. A sequence of cloudscapes, speeded up 72 times, showing cumulus formations up to 1,000 m high. The commentary informs us that at -12 degrees C, the droplets were drawn on the spider's web, these are known as drops of super-cool water and do not freeze. Droplets form on a laboratory glass plate and then disappear. Sequence of cumulus formation at high speed, occasionally shows flat areas at the top of the cloud indicating the formation of ice. Characteristic anvil-shaped clouds in a grey sky, contain mostly ice, over a line of trees on the edge of a field. CU of freezing drops of water, form into a snowflake on a glass plate. A scientist in a lab coat at the Puy de Dome Observatory, looks through his microscope in the laboratory. CU, cloud-forming instrumentation. BCU, a scientific implement prods a rod-shaped droplet on a glass plate and ice crystals begin to form. BCU on a glass plate with the ice-forming nucleus, cloud droplets form at -15 degrees C, looking like a snowflake on a black background. Similar, shows formation of an asymmetrical snowflake.

CU, heavy rain falling in the country, seen against a dark tree, a wind blows the bushes. The left hand arc of a rainbow as it touches the horizon on a threatening sky. Similar with right side of rainbow arc, on a wooded hill below a black sky with brightly lit clouds. Closer view of the same.

In a short sequence, a young man helps in an experiment by releasing a jet of propane in a misty field at -2 degrees C, causing the formation of a lot of ice crystals which are scattered in the fog. The commentary describes how droplets form crystals which fall to the ground as snow. Wider view as young man continues to release propane cloud in the field. BCU of a glass plate with greatly enlarged image of needles of ice tangled together. The sequence continues, showing increasingly heavy falls of snow against a dark bramble hedge. A wide view of the assistant, he walks out of the field with his propane gas bottle, the mist has disappeared, tilt up to a hazy blue sky.

Series of animated illustrations demonstrate how clouds can form to a height of 6Km (up to -15 degrees C) without ice forming, from there on, ice crystals form and depending on their size, can become subject to gravity and fall as snowflakes, gathering droplets and weight as they fall. As they meet higher temperatures on their descent, they fall as rain. The animation continues, it shows cloud where ice-forming nuclei are very sparse but therefore become larger to form hailstones, too big to melt before they hit the ground.

A second series of illustrations demonstrates how artificial ice-forming nuclei, like silver iodide smoke, can produce ice at only -4 degrees C. A third sequence shows how sodium chloride injected into a low cloud at temperatures above zero degrees C, can be made to induce rain, called "rain by chain reaction". A high speed sequence of low flat cloud movement, clouds at sunset and others.

The commentary says that on 30th August 1955, a cumuli nimbus ravaged villages in SW France with hailstones, a very dark cloud rolls across a silhouetted line of trees and telegraph poles. Forked lightning in a black sky. A gendarme seated behind a large wooden desk, picks up the telephone and takes notes. CU, a man burns charcoal impregnated with silver iodide in a wire bin. The charcoal smoke rises from the wire bin hung against a wall. Similar at night, with glowing charcoal in the suspended wire bin.

A sunlit winter landscape with village houses across scrubland, banks of low clouds roll over the houses. Storm clouds billow in a dark sky. Rose-coloured clouds lit from below, possibly at sunrise. CU, a man looks through an instrument on a tripod, possibly a camera, at distant mountains. A man with a tripod on the roof of his house. Closer view of the same on his tiled roof.

A sequence in Mexico shows a scientist in a desert area with low cacti, he holds up an instrument comprising four jets of air for experimenting on spiders' webs, particles are projected onto glass plates, he hands these to his assistant, he looks at them through a microscope at the window of his university laboratory. He walks in the university grounds with two students or assistants. A black snow-capped mountain. Researchers gather snow at 5,000 feet.

A large riverboat is moored on a river in the Congo, Africa. Children splash in the river below, something is thrown from the boat and they dive towards it. A low cloud over the silhouette of a tropical forest. Date palms stand on the riverbank, clouds pass (speeded up photography). A European couple load a rocket with salt crystals on their veranda. The rocket takes off from the back of a pick-up truck. The rocket's trail is seen against the cloud above it. Smoke from the rocket blast billows around the pick-up truck.

Another sequence in Ukelela (phonetic spelling) in Africa, shows a meteorological experiment with great grass fires lit over 20-25 hectares, and, the commentary tells us, they succeed in artificially creating cumulus clouds. Smoke from the fire rises and clouds form, billowing white clouds become dark and move overhead. Black clouds form against a red sky. The sun sets (speeded up photography), seen from the shores of a vast river with date palms in the foreground.

A sequence from the Puy de Dome Observatory in France, above "seas" of cloud in the valley below, very beautiful clouds roll off the hills in torrents, round a volcano summit, and wash around the base of black mountains.

Pan along a silhouetted mountain range and red sky. A distant mountain range seen across a sea of cloud. Mont Blanc seen from 305 Km with the aid of a red filter.

A sunset over a sea of cloud. Dawn over a dark landscape. Series of highly lit clouds at different times of day, very dramatic and beautiful.


To request more details on this film, please contact us quoting Film number 9807.