Cover of Electrostatics--Exploring, Controlling, and Using Static Electricity

Electrostatics--Exploring, Controlling, and Using Static Electricity

A. D. Moore

(1997) 248 pages

For those with a curiosity for the phenomena of static electricity, this sought-after classic remains the layperson's guide and introduction to electrostatics.

It can be enjoyed and easily understood by anyone from a high schooler searching for a science fair project to an industry professional.

Originally published as part of MIT's Science Study Series

This second edition includes the Dirod Manual

More about this book

Moore takes the mystery out of electrostatics with clear, concise explanations of the theory behind the spark. It is especially prized for its numerous demonstrations of electrostatic phenomena, some of which have never been fully explained.

After the initial publication of this book, A. D. continued working on his Dirods and demonstrations to simplify their construction and make them accessible to everyone. Now, for the first time, part 2 of this second edition includes his Dirod Manual and documents these hints and techniques.

The late A. D. Moore spent his years after retirement from the University of Michigan, Ann Arbor, lecturing and to demonstrating his "Electrostatic Zoo" to high school and college classes throughout the U. S., Canada, and Europe.

This second edition of the book represents the first opportunity to read all of A. D.'s refreshing and creative approach to electrostatic experimentation. The master of the demonstration has influenced countless inventors and science teachers-you will also be energized to step into the lab and generate your own sparks.


Part 1 Electrostatics:

High Voltage

Electrical Hazards; Discharges from Small Electrostatic Generators

Frictional Electricity

The World's First Generator; Friction-type Generators; The Van de Graaff Generator; Frictional Electricity—Troubles and Hazards; What Goes On Here?

Let's Talk About Charges

What This Chapter Will Do for You; Atoms, Protons, Electrons, and Ions; Some Practice with Big Numbers; A Little Aluminum Cube; An Enormous Force; What Is Charge?

The Dirods

Induction-type Generators; Induced Charges; Collecting the Charges; Generator Buildup, and Compound Interest; Where Does a Dirod Get Its Initial Charge?; How Do the Charges Move Around? The Electron Cloud; Conduction and Conductors; The Dirod Family

Improving the Generator and Learning More about Electrostatics

More Rods and Faster Build-up; Generator Spark-over—the Spark Shield; The Brush Problem; What Comes Next?

Electric Fields

The Field of Two Parallel Rods; The Nonuniform Field; Potential Difference and Field Intensity; Electric Flux; More about Forces—the Coulomb Force; Alignment with the Field—Field Shape Indicator; A Nonuniform Field and the Uniform Field; The Sphere Gap and the Rod Gap; Induction of Charge, and Field Shape; Conductors and Insulators in a Field; Faraday's Famous Ice Pail Experiment; The Faraday Cage


Visible Corona; Active and Passive Electrodes—The Breakdown of Air; More about Corona in a Dirod; Balanced Corona, and an Analogy; Generator Voltage Not Fixed by Speed; Suppressing Corona

The Electric Wind

Other Corona Effects; Precipitation; The Electric Fly, or Pinwheel; The Electric Blower; Demonstration of Smoke Precipitation; The Uncertain Soap Bubble; The Electric Wind and the Candle Flame; Electrostatic Precipitation Put to Use; How These Precipitators Work

More Demonstrations

Separation of Mixtures; The Little Island That Runs Away; The Electrified Water Spray; The Clapper; Franklin's Electrostatic Motor; The Dirod as a Motor; The Interdigital Motor; The Plateful of Balls; The Ball Box; The Electrostatic Separation Industry; Demonstrations with Liquids; One Type of Electrostatic Separator; Separation without Corona

More Service from Corona

Electrocoating; Electrostatic Sandpaper; Carpets, Upholstery, and Velvet Walls; Insecticides; Xerox; Electrostatic Printing; Electrostatic Spray Painting

Fun with Capacitors

What Is a Capacitor?; Amount of Capacitance—the Farad; Dielectrics; A Kitchen-made Capacitor; The Horizontal Capacitor; Sphere Gap Discharge of Capacitor; Separately Excited Dirod; Dirods in Parallel; The Roller; The Rockers; Capacitor Relationships; More about Certain Capacitors; Unexpected Shocks from Capacitors


The Vertical Capacitor; Figuring Capacitance; Other Experiments; Figuring Capacitance; Capacitors with Dielectrics; Combinations of Capacitors; More Remarks about Capacitors

Atmospheric Electrostatics

Charged Clouds, and the Electric Field We Live In; Lightning; Lightning Rods; Ball Lightning; Ions Charging Cloud Droplets; Charges Induced on Raindrops in Clouds; Charged Droplets from Bubbles Breaking; Are Tornadoes Powered by Charges?

Some More Electrostatic Generators

The Kelvin Generator; The Flapper; The Neon Lamp Bank; Shake-sphere Generators; The Swing Generator; More about the Radial Dirods; Dream Up Your Own!

On This and That

Why Dust Sticks; Are Negative Ions Good for Us?; Ions in Liquids and Solids; The Electret; The Electrostatic Speaker; The Most Remarkable Capacitors Are Inside of You; Some New Electrostatic Developments; The Future of Electrostatics

Some Final Hints

Corona Phenomena in More Detail; Sphere Gap Data; Field Shape Indicator Details; Plans for the Kelvin Generator; Materials and Methods; More about the Dirod Family; Building Dirod Junior; Building Radial Dirod Junior

Part 2 The Dirod Manual


History; The Teaching of Electrostatics; Feedback; Science Fairs; Safety

How a Dirod Works

How a Dirod Charges Up; Buildup is Geometric; Electrical Discharges—Sparks and Corona; Ions; Watching Corona; Designing for High Voltage; Dirod Polarity Reversal

Materials, Sources, Methods

Brass and Aluminum; Brush Material; Plexiglas; Corona Shields; Epoxy Adhesive; Corona Dope and TV Tubekoat; Nonmetallic Inductors and Collectors

Building Your Dirod

The Drawings; Two Ways to Make a Dirod; The Base; Bearing Posts; Shaft, Bearings, and End Stops; The Panel; The Rotor; Making the Disks; Mounting Discs on Shaft; Rodding the Rotor; The Pulley and Belt; The Motor and Speed Control; The Brushes; The Neutral Connector; The Dirod Terminals; Lengthening the Machine; The Self-excited Dirod; Separate Excitation; The Capacitor

Making the Accessories

The Bobber; Plugs and Receptacles; Connectors—Capacitor Plates to Inductors; Operational Flexibility; More about Capacitance; Two Kinds of Connectors; The Rod Gap—Measuring High Voltage

The Demonstrations

Preliminary Demonstrations Notes; Materials; Dirod Behavior when Loaded; Polarity Indicator; Cups that Repel; The Ping Pong Pair; Water Spray; Clatterbox; Two-ball Clatterbox; Lid Motor; Tri-Motor; Marble Motor; Cup Motor; Electric Pinwheel; Electric Blower; Precipitation; The Hailstorm; Separating a Mixture; Popcorn; Franklin Motor; Field Indicator; Leyden Jars; Levitation; The Jumper; The Rockers; The Ball Race; "Perpetual Motion"; Tassels Terrific; Spray Painting

A Final Word

Electrostatic Hazards; Materials List;


A. D. Moore Remembered by his Children;




"…an enjoyable, easy to read book…" (IEEE Electrical Insulation Magazine)

A.D. Moore, a pioneer in electrostatic generation, obviously had a passion for designing and building machines that generate high voltages through the use of electrostatics. His conversational approach to describing the operation of electrostatic machines makes for an enjoyable, easy to read book.

At first glance, you might think this book is too simplistic for use in an industrial or university laboratory. But surprisingly, there are plenty of very practical and insightful techniques for measuring and understanding high voltage and electrostatic charge.

This book would be useful for an experimentalist or hobbyist interested in designing, building, and experimenting with electrostatic generators.

Some of the topics covered include: fundamentals of electrostatic charging, building induction generators, constructing high voltage capacitors, building the dirod generator, techniques for reducing corona, measuring high voltage using neon lamps and sphere gaps, and generating electric wind.

"…exceptionally clear and direct…" (Science Teacher Magazine)

Electrostatics is more than a book about static electricity. It is the reader's opportunity to learn from A. D. Moore (1895-1989), the author and unquestioned authority on static electricity, as he recounts his lifetime of experimentation and invention.

The book is written in an exceptionally clear and direct prose that is so conversational that the reader might think he or she is actually hearing the author talk about the history of the exploration of static electricity, the discoveries leading to its harnessing, and the applications to which it has been put.

Moore's explanations of atomic structure, electrical fields, capacitance, coulomb forces, and so forth are so simple that they are easily understood at the high school level. This book is so full of information that it will also serve college students well. Examples and historical anecdotes reinforce factual information. Teachers can profit from studying Moore's style of presentation.

The first section of the book focuses on the theory of static electricity and the evolution of the theoretical principles. Proper attention is given to earlier contributors such as Franklin, Faraday, Kelvin, Maxwell, and Van de Graaff. The second section of the book explains how to construct one's own electrostatic generator.

The explanations are clear and precise with easy-to-follow diagrams and a list of materials. Any teacher who wants an electrostatic generator can easily construct one as a class project.

The third section of this book is a series of 25 demonstrations of electrostatic properties and phenomena that can be used in classrooms or as the basis for science fair projects. The demonstrations represent a broad spectrum of sophistication-from the repulsion of two Styrofoam cups to the "pizza pan perpetual motion"experiment. Demonstrations, however are not limited to this section of the book. Soap bubbles, candle flames, kitchen-made capacitors, and smoke precipitation are but a few of the demonstrations throughout the book.

The book was first written 1968, but to the credit of the author it has a freshness that makes it instructive and highly interest) book for today. It is a good addition to the school or classroom library.

"…Highly recommended…" (Library Journal)

Moore has captured the broad field of electrostatics and its applications to evoke near universal reader appeal. Designed primarily for the young student or layman, it should be a rich source of diversion and inspiration to the engineer, scientist, and experimenter.

He presents the material in a thoroughly fascinating, understandable, accurate way without resorting to distracting mathematical proof…Highly recommended for specialists, informed readers, and the young adult. Library Journal

"…it remains one of my favorites…" (Scott Miller, Senior Research Scientist, Battelle Memorial Inst.)

What a joy it was to find A.D. Moore in print again after all these years…it remains one of my favorites. I look forward to introducing my young son to the pleasures of 80 KV dirod generators.

What a wonderful job, to be able to bring this information to new generations