December 1960 Popular Electronics
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
We are moving into the colder
days of the year in the northern hemisphere. The normal high temperature here in Erie,
Pennsylvania is around 49°F (35° today with snow on the ground for the last three days).
It is the time of year that causes those less appreciative of cold weather to conjure
up memories of warm summer days with green leaves on tree branches and colorful flowers
in the garden. For those of you like me who actually prefer the cooler weather, this
Carl & Jerry story about making snow by blasting clouds with ultrasonic energy just
adds to my appreciation of the onset of winter and visions of a white Christmas. To date
there has been no major, efficient progress in the field of snowmaking or rainmaking
(other than seeding
clouds with silver iodide). Ski resorts still need sub-freezing weather for their
snow machines to work using a ground-based water source (not directly from the clouds).
Carl & Jerry: The Snow Machine
By John T. Frye W9EGV
Carl and Jerry were sitting in Mr. Gruber's study listening with deep interest to
what their elderly neighbor and friend was saying.
"People today don't know what snow is," he snorted, his bright blue eyes flashing
in his wrinkled face. "When I was a boy, the first snow usually fell around Thanksgiving;
and many times we never saw bare ground again all winter. The snow was deep, too; and
they needn't try and tell me it only seemed so because I was measuring it against my
shorter boyish legs."
The boys waited expectantly to see what would follow Mr. Gruber's reference to his
boyhood. They knew that with Mr. Gruber the past was simply a storehouse where he went
to get an experience or a memory that could be of current use. He did not live there,
as many old people do. He lived in the present and in the future. He knew far more about
missiles and satellites than either Carl or Jerry, and he had a keen, daring mind.
"I've read that this part of the world has been experiencing a warming trend for the
last several years," Jerry offered.
"It's high time they admitted it," Mr. Gruber said, getting to his feet. He put on
his battered derby hat and tapped it into place with a firm slap on the crown. "You boys
come on out to the shop. I've got something to show you."
The boys put on their coats and followed the old gentleman out the back door into
the rapidly fading winter day. There was a damp chill in the air and a low bank of clouds
in the southwest.
"A couple of nights ago my nephew - that's my wife's sister's boy - dropped in to
see us," Mr. Gruber explained. "He's a salesman for a West Coast electronics outfit,
and he had a demonstration unit with him that I know will interest you two. He tows it
behind his car in that trailer sitting beside the garage; but we rolled the gadget out
and into the shop."
As they stepped into the small, neat workshop, Carl and Jerry saw a bulky
piece of electronic gear standing on heavy rollers in the middle of the floor. Several
panels were arranged in a special shielded rack, and they carried a dazzling array of
meters, knobs, vari-colored pilot lamps, and push-buttons. One heavy cable ran from the
cabinet to the 220-volt outlet box on the wall. Another ran to what looked like an extremely
heavy-duty speaker mounted in a gimbal-like arrangement that permitted it to be pointed
in any direction by proper adjustment of a pair of hand-wheels. This apparatus rested
on its own set of rollers. When the boys examined it closely, they saw that the cone
of the "speaker" was made of heavy steel that looked like boiler plate.
"What on earth is it?" Carl asked in awe. "It's a super-duper, high-power ultrasonic
amplifier," Mr. Gruber explained, patting the rack-and-panel fondly. "If I've got my
figures straight, it costs around $80,000; it uses tubes with 7000 volts on the plates
drawing 3 amperes of current; and it puts 350 volts at 30 amperes on the voice coil of
the transducer there."
"Whe-e-e-ew!" Jerry whistled softly, "ten and a half kilowatts of audio power! What's
it do besides split eardrums?"
"For one thing, manufacturers use it to check the effect of ultrasonic vibrations,
such as those produced by air-buffeting at extreme speeds, on products designed to be
mounted in missiles. You boys weren't around when my nephew had it going. He was called
home to California suddenly because his father suffered a heart attack, but he taught
me how to run it and said I could show it to you."
As he finished speaking, Mr. Gruber up-ended an empty cardboard carton on top of a
block of wood with the open side of the box facing the transducer. A large Coca Cola
bottle was placed well back in the carton, and the block of wood was slid to within about
three feet of the cone. Then the transducer was aimed directly at the center of the bottle.
"Put these in your ears," Mr. Gruber directed as he handed the boys some rubber ear
plugs. "The frequency is too high to be heard as sound, but we don't want to take any
chance on injuring our ear drums."
A few moments later Mr. Gruber said, "I guess we're ready, then," a little nervously.
He reached over and gingerly pushed a button on the panel of the instrument. A green
pilot lamp came on, and a low hum issued from deep inside the rack. After about a minute
an orange lamp began to glow.
"Stand back!" Mr. Gruber shouted to the boys as he crouched down beside the rack and
pushed another button. A red pilot lamp flashed on, and the hum increased. Very slowly
Mr. Gruber began to turn a control on the top panel clockwise; he had hardly advanced
it a fourth of a revolution when there was a brittle snapping sound, and the bottle flew
"Literally shook to pieces by ultrasonic waves!" Mr. Gruber exclaimed happily as he
examined the little pieces of glass scattered over the bottom of the carton. "But let's
go back to the house. I want your opinion about something, and it's too cold out here
for my tired blood."
"What I'm going to suggest may sound pretty silly to you," Mr. Gruber warned as they
settled down in the study and he took a little red notebook from his pocket; "but it's
gotta come out; so here goes:
"For a long time now I've been interested in snow, especially in how it's produced
naturally and in the experiments to produce it artificially. Snow is a solid form of
water which grows while floating, rising, or falling in the free air of the atmosphere.
It begins ordinarily in a cloud of moist air that's super-cooled below the freezing temperature
of water, but the particles of moisture don't crystallize into snow until they find a
nucleus around which they can cluster. Once a crystal is started, it moves up and down
through the cloud, gathering more and more ice, until finally it's heavy enough to fall
to earth as a snowflake; or, if the lower atmosphere is warm enough to melt it, as a
rain drop. Yes, even on the hottest August afternoon, a rain shower was once a snow shower
in the upper atmosphere.
in 1946 Vincent Schaefer of the General Electric Research Laboratories transformed a
super-cooled, four-mile-long, alto-stratus cloud into snow by 'seeding' it with only
six pounds of solid carbon dioxide. Later B. Vonnegut, a co-worker of Schaefer's, found
that silver iodide was particularly effective as a seeding nucleus because its structure
matched the structure of ice to within 1%. But there is apparently another way ice crystals
can be formed - by the sudden rarefaction of cold, moist air, such as is produced by
detonation, adiabatic expansion, high-velocity missiles, or vortices which cool the air
abruptly below the water transition temperature of -38° F. It's believed that this
is what causes vapor trails behind high-flying planes.
"Now you boys know," Mr. Gruber continued slowly, "that a sound wave creates alternate
areas of compression and rarefaction in the atmosphere. I've long wondered if powerful
sound waves directed into a proper cloud might not produce ice crystals that could grow
into snowflakes. I never hoped to have the apparatus to carry out such an experiment;
but suddenly it's sitting right out there in my shop. Maybe you boys would like to help
me try the experiment after supper. I've been watching the weather closely, and conditions
should be about right."
"Would we ever!" Carl exclaimed.
"We'll be here," Jerry promised as he reached for his jacket; "but the forecast calls
for cold and cloudy weather with no precipitation; so if we have any snow, I guess you'll
have to make it."
It was around eight o'clock when the three of them gathered in Mr. Gruber's shop.
A lighted gas trash-burner in the corner took the chill off the interior, but it was
bone-chilling cold and damp outside. Carefully they wheeled the amplifier and the transducer
out on the concrete apron behind the shop and pointed the cone straight up.
The apparatus was turned on, and as it warmed up Mr. Gruber carefully noted the temperature,
humidity, and atmospheric pressure in his little red notebook. Then he threw on the power
and firmly advanced the power output control as far as it would go. As the boys watched,
their ear plugs in place, he used the hand-wheels to sweep the amplifier's ultrasonic
beam carefully back and forth.
This went on for several minutes. Suddenly something that felt like a light cobweb
brushed Jerry's cheek. At the same time Mr. Gruber snatched off his derby hat and dashed
into the lighted shop with it.
"Diamond dust!" he shouted triumphantly as he pointed to gleaming specks sprinkled
over the crown of the derby. "That's what they call these tiny ice crystals that form
close to the ground, usually in very cold weather. Now if they will just move up and
down through the clouds, we may have some real snowflakes soon. Back to the snow machine,
The little diamond dust particles must have danced up and down in the clouds just
as Mr. Gruber hoped they would, for soon honest-to-goodness snowflakes began to fall.
They were small and scattered at first, but they rapidly increased in size and frequency;
it became necessary to shut off the amplifier and wheel it into the shop.
old man stood in the open doorway watching anxiously to see if the snow would stop, but
instead the flakes grew larger and thicker.
When the boys finally went home, there was already a couple of inches of snow on the
ground, and it was snowing harder than ever; but the ten-o'clock TV weatherman said it
was just a freak snow shower and would soon end.
The weatherman was wrong, though, very wrong. When Jerry was awakened next morning
by the sound of snow shovels scraping on the sidewalk, it was snowing so hard he could
scarcely see across the street; and there was a good foot of snow on the ground. As soon
as breakfast was over, he grabbed his snow shovel and headed for Mr. Gruber's house.
Carl was already busy cleaning off the old man's walk; and the latter, a scarf tied over
the top of his derby and beneath his chin, was literally dancing in his own personal
"Now these whippersnappers can see what an old-fashioned snow really looks like!"
It never let up a minute the whole day. By evening, traffic in the city was at a complete
standstill. The mayor went on the local radio station and asked everyone to remain calm
in the emergency. Citizens were requested to stay in their homes and to be exceptionally
careful of fire, since fire trucks could not get through the snow-clogged streets.
All of the weather forecasters were frankly astonished at the storm. They said it
was a freak affair that could happen only once in a thousand times. Warm, moist air coming
up from the Gulf had been suddenly lifted by a narrow wedge of polar air that had knifed
down from Canada; and the front that resulted had stalled directly over the city. With
two feet of snow in town, bare earth could be seen not fifty miles away.
Mr. Gruber telephoned right after the news broadcast and asked both boys to come to
his shop. They floundered through the high snow banks, and as they stepped through the
door they saw Mr. Gruber toss the little red notebook with all his records of the snow-making
experiment into the trash burner. He looked sick.
is a terrible, terrible thing, boys, and it's all my fault," he groaned. "This is what
happens when you rashly undertake an experiment without considering all the possibilities.
I want you two to promise me you will never tell anyone what we discovered last night.
Power to make it snow is too dangerous to rest in human hands."
The boys promised and did their best to cheer him up, but it was no use. He turned
off the lights and trudged wearily through the snow to his back door.
"Wait, Mr. Gruber!" Carl suddenly called, as he lifted a startled face to the sky.
"It's stopped snowing!"
"Thank heaven!" the old man exclaimed.
He straightened up and saw it was true. "Now I can sleep. Good night, boys."
Carl and Jerry stood outside between their houses for a few minutes and watched the
stars peep out one by one. Finally the moon slid from behind a cloud and bathed the snowy
landscape in a beautiful white light.
"Jer," Carl finally asked as he stared up at the sky, "do you really think that the
machine caused all this snow?"
"We'll probably never know," Jerry said slowly; "but no one will ever convince Mr.
Gruber that it didn't. As for me, whether the machine worked or not, it has taught me
a lesson I'll never forget: power carries with it a terrible responsibility. Good night,
Carl & Jerry: Their Complete Adventures is now available. "From
1954 through 1964, Popular Electronics published 119 adventures of Carl Anderson and Jerry Bishop, two teen boys with
a passion for electronics and a knack for getting into and out of trouble with haywire lashups built
in Jerry's basement. Better still, the boys explained how it all worked, and in doing so, launched countless
young people into careers in science and technology. Now, for the first time ever, the full run of Carl
and Jerry yarns by John T. Frye are available again, in five authorized anthologies that include the
full text and all illustrations."
Carl & Jerry Episodes on RF Cafe
- Electronic Eraser,
- Electronic Trap, March
- Geniuses at Work, June
- Eeeeelectricity!, November
- Anchors Aweigh, July
- Bosco Has His Day,
- The Hand of Selene,
- Feedback, May 1956
- Abetting or Not?, October
- Electronic Beach
Buggy, September 1956
- Extra Sensory
Perception, December 1956
- Trapped in a Chimney,
- Command Performance,
Education, July 1963
- Treachery of Judas, July
- The Sucker, May 1963
- Stereotaped New
Year, January 1963
- The Snow Machine, December
Education, July 1963
- Slow Motion for
Quick Action, April 1963
- Sonar Sleuthing, August
- TV Antennas, August 1955
- Succoring a Soroban,
- "All's Fair --", September
- Operation Worm Warming,
Stomping, March 1962
- The Blubber Banisher,
- The Sparkling Light, May
- Pure Research Rewarded,
- A Hot Idea, March 1960
- The Hot Dog Case, December
- A New Company is Launched,
- Under the Mistletoe,
- Electronic Eraser,
- "BBI", May 1959
- Ultrasonic Sound Waves,
- The River Sniffer, July
- Ham Radio, April 1955
- El Torero Electronico,
- Wired Wireless, January
- Electronic Shadow,
- Elementary Induction,
- He Went That-a-Way,
- Electronic Detective,
- Aiding an Instinct,
- Two Detectors, February
- Tussle with a Tachometer,
- Therry and the Pirates,
- The Crazy Clock Caper,
Posted November 14, 2018