Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
In "The River Sniffer,"
our intrepid sleuthing heroes Carl and Jerry, the creation of John T. Frye,
apply their electronics prowess and lessons remembered from chemistry class at Parvoo
University in order to catch polluters who are dumping chemicals into the river
where they like to fish. I always like being reminded of something long forgotten
when reading an article from vintage magazines like this 1962 issue of Popular
Electronics, and this one did not disappoint. Do you recall what 'pH' stands
for as a measure acidity or alkalinity? It means 'potential
Hydrogen ion concentration.' Don't thank me if it jogged your memory
as well - thank Carl and Jerry.
Carl and Jerry, The River Sniffer
A Carl and Jerry Adventure
By John T. Frye, W9EGV
is the life," Carl sighed contentedly; "no lessons, no exams, no ROTC drills, no
nothin'!" He and his friend, Jerry, were sprawled on their backs on the river bank
staring upward through the sycamore leaves at a buzzard sail-planning in the cloudless
summer sky above. Down at the edge of the water, two fishing rods rested in a couple
of forked sticks.
Before Jerry could answer, a slight splashing from the river attracted his attention.
Raising himself on one elbow so that he could get a better look, he exclaimed, "Hey,
Carl, look at those fish on top of the water!"
Two large bass were threshing about on the surface, obviously in their dying
throes. Even as the boys watched, the splendid fish turned belly-up and floated
quietly downstream; and, looking more closely, Carl and Jerry saw that the two were
accompanied by other dead and dying fish of various sizes.
The throbbing of an outboard motor was heard downriver, and an aluminum boat
carrying a young man dressed in a game warden's uniform came in sight around a bend
in the stream. When he saw the boys, he ran the bow of the boat up on the bank,
cut the motor. and stepped out.
"That's a mighty sorry sight," he remarked, motioning toward the floating fish.
"I'd certainly like to catch whoever keeps dumping that fish-killing stuff into
"You mean it has happened before?" Carl queried.
"About once a week all spring, but not always on the same day or night. When
someone calls in and reports dead fish, I get right on it; but I never know how
far the fish float after dying. However, this is the farthest upstream I've found
them, and some of those fish are still wiggling. This time, at least, the stuff
must have entered the river from this bank and not too far upstream; but I've covered
every foot of the river for five miles in either direction without finding a single
likely source of pollution. If only I had some way of knowing just as soon as the
stuff hit the river - even before the fish began to die - I'd stand a chance of
tracing it. At least I could collect a strong enough sample for accurate analysis
before the polluting substance was too greatly diluted."
Jerry was looking very interested.
"You mean you need some kind of a robot to sample the river water continuously
and give some sort of alarm when an unusual amount of destructive chemical floats
past it ?"
"Exactly, but I guess there's no such gadget."
"Don't make book on it. I have an idea: if you'll take that glass jug lying in
the weeds across to the other side of the river and fill it, my friend here and
I will try to build such a robot for you. Electronics is our field. I can't promise
anything, but you can give us your telephone number and we'll call you if we come
up with something."
"Okay, what have I got to lose? But what do you want with the water?"
"We'll need a sample of normal, unpolluted river water to work with."
While Bill Herber, the game warden, was collecting the water, Carl and Jerry
reeled in their lines. A half hour later they were entering the coolness of their
basement laboratory at Jerry's home, and Jerry went straight to a stack of papers
resting on a shelf. He sorted through them until he found what he sought.
"Ah, here it is," he said. "I was sure I had saved the description of the River
Robot Monitor that Mr. Edward J. Cleary, Executive Director of ORSANCO, sent me."
"Bully for you; so what is it?"
"It's a unit of a system of continuous automatic electronic river pollution monitors
used by the Ohio River Valley Water Sanitation Commission to keep a continuous check
on the Ohio River water. Eleven of these unattended robot devices are strung along
the river. They constantly test the water for seven different variables: dissolved
oxygen, chloride, hydrogen ion, specific conductance, oxidation-reduction potential,
temperature, and solar radiation. The various sensors feed their information into
a telemeter transmitter at each location, and all the transmitters are connected
by telephone wires to a telemeter receiver in Cincinnati. At regular intervals this
receiver calls each monitor for a report. Signals received actuate a transcriber
which automatically types the information on tabulation sheets for diagnosis of
"So that's why you told Mr. Herber not to bet there wasn't a river robot monitor!
We're not going to try to build one of these robots, are we?"
"Hardly. They're quite complicated and cost a lot of money. But I'm hoping we
can build a simple gadget based on a single sensing unit that will serve our purpose."
"How about the hydrogen ion measuring part? If I remember my chemistry, that's
an indication of the acidity of a solution."
"Either the acidity or alkalinity of the solution," Jerry corrected. "If you
recall, the potential hydrogen ion concentration, or pH factor, is measured on a
0-14 scale, with 7 being the number associated with 'pure water.' Numbers going
downward from 7 indicate increasingly acid solutions. Readings going upward from
7 indicate increasingly strong base solutions. Since the number is actually the
negative logarithm of the hydrogen ion concentration, each pH unit represents a
ten-fold change in solution strength. Compared to a pH 5 solution, a pH 4 solution
is ten times more acid, and a pH 3 solution is a hundred times more acid.
"One way to measure the pH of a solution," he continued, "is to add special organic
indicators and observe the color change that results. A better method, in many respects,
is to employ an electro-metric device that translates the pH of the solution into
a reading on a meter whose scale is marked off in pH units. That's the kind of pH
indicator our chemistry prof at Parvoo University used in his lectures last year."
"Fine. All we have to do is build a pH meter and let the meter-deflecting current
also operate a sensitive relay that will sound an alarm."
"It's not that easy," Jerry demurred.
"Until I read this pamphlet called 'The Development of pH Instrumentation' by
A. O. Beckman of Beckman Instruments, Fullerton, California, I had a hazy notion
a pH meter was a relatively simple gadget that employed either a current conducted
through the solution or a voltage produced by galvanic action on electrodes immersed
in the solution to deflect a meter. Actually the latter principle is the one employed,
but both the electrode used and the indicating meter are very special types.
"Oxidizing of ordinary metallic electrodes immersed directly in the solution
prohibits their use; so a special 'glass electrode' is employed. Picture an electrode
surrounded by a low-resistance, non-oxidizing solution in a test tube that's immersed
in a solution being tested. The test tube wall keeps the solution being tested from
oxidizing the electrode, but a voltage appears across this glass membrane which
is proportional to the difference in hydrogen ion concentration of the solution
on either side. As you can guess, this glass electrode is an extremely high resistance
device, and special means are necessary to measure the voltage developed. In practice,
a not-too-simple feedback amplifier translates this voltage into meter-deflecting
"Say no more; we'll not try to build a pH meter. Got any other ideas?"
"Yes. We know that the presence of acid greatly influences the conductivity of
a solution. What say we build a simple bridge circuit in which two legs are fixed
resistors, a third leg is the resistance appearing between two electrodes immersed
in the river, and the fourth leg is a variable bridge-balancing resistor in series
with a special temperature-sensitive resistor also in the water? We can drive the
bridge with a few volts of a.c. produced by a simple transistorized chopper."
the temperature-sensitive resistor and why the a.c.?" Carl wanted to know.
"D.c. would quickly polarize our electrodes and render them useless," Jerry replied.
"Also, conductivity changes considerably with temperature, and we want our device
to respond only to chemical change; so we must compensate the bridge for the effect
of temperature change in the river water. A little battery-powered transistorized
amplifier will magnify any a.c. voltage resulting from bridge unbalance.
"This amplified output can be rectified with a diode," Jerry went on, "and used
to drive a meter and a sensitive relay connected in series. An increase or decrease
in the conductivity of the water flowing past the electrodes will unbalance the
bridge and cause the relay contacts to close and the meter to read upscale. Closing
of the contacts can sound an alarm."
"Sounds good; let's try it," Carl said, rubbing his hands impatiently.
Like most electronic devices, the "river sniffer," as the boys dubbed their brain
child, was not nearly so easy to put into practice as it sounded in theory. They
spent three full days building a really stable transistorized amplifier, finding
the proper thermistor to keep the bridge balanced during a 20° temperature change
in their jug of river water, and adjusting the sensitivity of the relay so that
it remained open with the electrodes in a weak salt solution but closed when the
solution was weakened with more water or strengthened with a little more salt. Finally,
though, they were partially satisfied with the operation of their invention - a
good technician is rarely completely satisfied - and they called Mr. Herber.
He drove them to a farmhouse where he kept his boat, about a quarter of a mile
upstream from where they had met him. The river sniffer, housed in a weatherproof
box, was installed on the river bank; and the sensing electrodes were placed well
out in the current. Jerry carefully balanced the bridge with the aid of the indicating
A bell was installed in the farmer's house and connected with a bell transformer
and the contacts of the sniffer's relay so that the closing of the contacts would
ring the bell. Then, after extracting a promise from the farmer to call Mr. Herber
immediately if the bell rang, they left the robot to its sentry duty.
It was shortly after midnight that same night when Jerry's telephone rang.
"Hi," said the voice of Mr. Herber, "the farmer says that gadget of yours is
ringing the bell off his wall. Want to go along and see what's up?"
"Sure," Jerry answered. "I'll get Carl, and we'll be out front waiting for you."
It did not take long to reach the farm.
The farmer, clad in his nightshirt, was sitting in his kitchen malevolently eying
the clanging bell on the wall. Jerry disconnected it; the farmer went back to bed;
and the boys and the game warden walked down to the river sniffer.
"Wow!" Jerry exclaimed as he lifted the lid and glanced at the meter reading
with the aid of his flashlight. "Something is really boosting the conductance. What
say we take the sniffer with us in your boat and see if we can't run down the source
of the pollution?"
In a few minutes they were heading upstream. Jerry was in the bow with his sniffer;
Carl was in the middle; and Bill Herber operated the outboard motor at the stern.
As the boat moved to the middle of the river, the meter reading declined; but swinging
back toward the bank pushed it higher than ever. It continued climbing slowly until
they were about a quarter of a mile upstream; then suddenly it dropped to the bridge-null
"Back up," Jerry said; "we've run out of it."
Mr. Herber reversed the boat's direction, and the meter reading shot upward.
The game warden then maneuvered the boat under Jerry's direction until it became
apparent the polluting substance was coming from beneath some low-hanging bushes
growing on the bank. Suddenly he revved up the motor and headed straight for these
bushes. As the boys ducked, branches scraped along the metal hull and the boat emerged
in a shallow creek whose mouth had been concealed by a thin screen of willows.
"Better watch your propeller," Jerry warned as he peered over the side with his
flashlight; "the water's not more than a foot deep."
"No sweat," Mr. Herber replied. "This motor doesn't have a propeller. It operates
on a jet principle and will run in four inches of water."
At this moment Jerry spied a trickle of water dribbling from a large tile set
in the bank of the creek, and a little checking with the river sniffer confirmed
that the water pollution was coming from this tile.
Bill Herber stepped out of the boat and motioned for the boys to follow him toward
a large concrete building a short distance away. A light was shining from the windows
and through the open door, and inside they found a young man busily pouring some
liquids from carboys into a large vat.
When Mr. Herber explained the reason for their visit, the young man shook his
head ruefully. "I'm afraid I'm the one you're looking for," he admitted. "The first
of the year I started a little plating business here. I use sulphuric acid to clean
the parts before putting them in the plating bath. About once a week I flush the
dirty and weakened acid down that sewer that leads into the crick and mix up a new
batch, as I'm doing now. I never thought about killing fish or causing any other
trouble, and I can assure you it won't happen again."
"I'm sure it won't," Mr. Herber said kindly, "but I'll have to report it, and
there's a fine for river pollution. I hope they go easy on you. Come on, boys; let's
get back to town."
As the game warden drove Carl and Jerry home, he declared, "I sure do appreciate
what you fellows did for me. I don't know how to thank you. I wish I had brains
enough to build something like that river sniffer of yours."
"We lucked out," Jerry said modestly.
"Had it been something other than a strong acid that was killing the fish, the
sniffer might not have worked so well. And as for paying us, how about showing us
a spot where we really can catch some fish?"
"That I can do. Be ready with your rods and a can of stinkworms about four o'clock
tomorrow afternoon, and I'll show you the best channel-cat fishing east of the Mississippi!"
Posted May 10, 2021
(updated from original post on 11/18/2013)
Carl Anderson and Jerry Bishop were two teenage boys whose
love of electronics, Ham radio, and all things technical afforded them ample opportunities
to satisfy their own curiosities, assist law enforcement and neighbors with solving
problems, and impressing – and sometimes toying with - friends based on their proclivity
for serious undertakings as well as fun.
- Carl &
Jerry: A Low Blow - March 1961
- The Black
Beast - May 1960
Electronik, September 1958
- Pi in
the Sky and Big Twist, February 1964
Bell Bull Session, December 1961
Boogie, August 1958
- TV Picture,
Eraser, August 1962
Trap, March 1956
at Work, June 1956
Aweigh, July 1956
Has His Day, August 1956
- The Hand
of Selene, November 1960
or Not?, October 1956
Electronic Beach Buggy, September 1956
Extra Sensory Perception, December 1956
in a Chimney, January 1956
Performance, November 1958
of Judas, July 1961
- The Sucker,
New Year, January 1963
Snow Machine, December 1960
Extracurricular Education, July 1963
Slow Motion for Quick Action, April 1963
Sleuthing, August 1963
- TV Antennas,
a Soroban, March 1963
Fair --", September 1963
Worm Warming, May 1961
Teaches Boy - February 1959
- Too Lucky
- August 1961
and Jeopardy - December 1963
Santa's Little Helpers - December 1955
Tough Customers - June 1960
Pocket Radio, TV Receivers
Yagi Antennas, May 1955
Stomping, March 1962
- The Blubber
Banisher, July 1959
- The Sparkling
Light, May 1962
Research Rewarded, June 1962
- A Hot Idea, March
- The Hot Dog
Case, December 1954
New Company is Launched, October 1956
the Mistletoe, December 1958
Eraser, August 1962
- "BBI", May 1959
Sound Waves, July 1955
- The River
Sniffer, July 1962
- Ham Radio,
Torero Electronico, April 1960
Wireless, January 1962
Electronic Shadow, September 1957
Induction, June 1963
- He Went
Detective, February 1958
an Instinct, December 1962
- Two Detectors,
with a Tachometer, July 1960
and the Pirates, April 1961
The Crazy Clock Caper, October 1960
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 lash-ups 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."