December 1960 Popular Electronics
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We are solidly into the hottest days of the year in the northern
hemisphere. The normal high temperature here in North Carolina
is 89°F. It is the time of year that causes those less appreciative
of hot, humid weather to conjure up memories of winter days
with evergreen tree branches bending under the weight of the
new-fallen snow. For those of you like me, here is a Carl &
Jerry story that might help relieve the anxiety associated with
knowing that in a few hours you will be walking out of an air
conditioned building into 90-something-degree air and onto a
blistering hot asphalt parking lot. AGW acolytes might find
the story useful for submission to the official database of
incontrovertible scientific evidence that the earth has been
heating up since right here in the 1960-dated article is a statement
of that observation by Mr. Gruber. The story centers around
a high-power audio snow generating contraption.
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
"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
"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
"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 to pieces.
"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.
"Back 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
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
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, men!"
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.
The old man stood in the open doorway watching anxiously
to see if the snow would stop, but instead the flakes grew larger
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 snowstorm.
"Now these whippersnappers can see what an old-fashioned
snow really looks like!" he gloated.
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
"This 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
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."
Carl & Jerry: Their Complete Adventures is now available. "From 1954 through 1964,
Popular Electronics published 119 adventures of Carl and Jerry, 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
- Carl & Jerry: Anchors Aweigh, July 1956
- Bosco Has His Day, August 1956
- The Hand of Selene, November 1960
- Feedback, May 1956
- Abetting or Not?, October 1956
- Electronic Beach Buggy, September
- Extra Sensory Perception, December
- Trapped in a Chimney, January 1956
- Command Performance, November 1958
- Extracurricular Education, July
- Treachery of Judas, July 1961
- The Sucker, May 1963
- Stereotaped New Year, January 1963
- The Snow Machine, December 1960
- Extracurricular Education, July
- Slow Motion for Quick Action,
- Sonar Sleuthing, August 1963
- TV Antennas, August 1955
- Succoring a Soroban, March 1963
- "All's Fair --", September 1963
- Operation Worm Warming, May 1961
- The Crazy Clock Caper, October 1960
- Two Detectors, February 1955
- Tussle with a Tachometer, July 1960
- Therry and the Pirates, April 1961
- The Sparkling Light, May 1962
- Pure Research Rewarded, June 1962
- A Hot Idea, March 1960
- The Hot Dog Case, December 1954
- A New Company is Launched, October 1956
- Under the Mistletoe, December 1958
- Electronic Eraser, August 1962
- Blubber Banisher, July 1959
- "BBI", May 1959
- Ultrasonic Sound Waves, July 1955
- The River Sniffer, July 1962
- Ham Radio, April 1955
- El Torero Electronico, April 1960
- Wired Wireless, January 1962
- Electronic Shadow, September 1957
- Elementary Induction, June 1963
- He Went That-a-Way, March1959
- Electronic Detective, February 1958
- Aiding an Instinct, December 1962
Posted July 10, 2014