1969
 

December, 1969. How to Make Photographs in Polymer and Build a Sensitive Pressure Gauge
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
November, 1969. Old Refrigerators Are Salvaged to Build a Laboratory Cooler and Gas Liquefier
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
October, 1969. The Flow of Blood, Weather Vanes, Telescope Mirrors and the Conductivity of Insulators
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1969. Antigens and Antibodies Are Studied By Their Diffusion Patterns in Agar
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
August, 1969. Color Photographs of the Night Sky Are Made By Refrigerating the Film
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
July, 1969. The Metabolic Rate of Small Animals Is Measured in a Homemade Apparatus
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1969. Salts React in a Gel to Make the Colorful Liesegang Bands
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1969. How to Blow Soap Bubbles That Last for Months or Even Years
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
April, 1969. The Lore and Aerodynamics of Making Flying Kites
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1969. Various Kinds of Chromatography, Especially the Thin-Layer Method
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
February, 1969. How to Construct an Argon Gas Laser with Outputs At Several Wavelengths
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
January, 1969. Simple Ways to Calculate the Orbits of Space Vehicles
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1968
 

December, 1968. How to Make a Wave Machine to Simulate the Building and Destruction of Beaches
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
November, 1968. Experiments with Various Liquids That Do Not Mix
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
October, 1968. An Ultraviolet Spectrograph Designed By the Illustrator of This Department
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
September, 1968. Making an Apparatus That Will Measure the Acidity or Alkalinity of Solutions
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
August, 1968. Analyzing How a Stone Skips and Turning Sound into Heat
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1968. How to Make Electrets, Devices That Hold Electrostatic Charge
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1968. A Plan for an Analogue Computer That Can Be Built for about $40
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1968. A Spectrophotometer Is Built for Less Than $75
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
April, 1968. Two Methods of Microscope Lighting That Produce Color
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1968. Little Radio Transmitters for Short-Range Telemetry
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
February, 1968. Building a Sensitive Magnetometer and an Accurate Solid State Timer
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1968. On Equipment to Study Freezing and on Growing Crystals of Salt
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1967
 

December, 1967. An Indian Mound Is Excavated By High School
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
November, 1967. How to Make an Electrochemical Cell and Also an Unusual Kind of Sundial
Cost:$0-100	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
October, 1967. How to "Sputter" Thin Films of Metal Onto Glass and Experiment with Them
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
September, 1967. How to Construct a Gas Chromatograph That Can Measure One Part in a Million
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
August, 1967. A Gauge to Measure Tiny Changes in Gas Pressure; Growth Substances in Plants
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1967. How to Construct Fluid Models That Simulate Fields of Force
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1967. A Sensitive Electronic Thermometer Used for Making a Study in Micrometeorology
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1967. How to Study Learning in the Sow Bug and Photograph Tiny Live Crustaceans
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
April, 1967. Little Pendulums That Oscillate Like Big Ones
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
March, 1967. Two Kinds of Apparatus for Growing Plants in a Controlled Environment
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
February, 1967. How to Make Holograms and Experiment with Them or Ready-Made Holograms
Cost:$0-100	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
January, 1967. The Study of Electrostatic Effects and Convection Currents in Liquids
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:

1966
 

December, 1966. An Amateur's Experiment in Animal Behavior and a Study of the Salty Rain of Venezuela
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
November, 1966. Two Devices for Electric Welding, One Using a Carbon Arc Torch and the Other a Rattrap
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
October, 1966. How to Build a Wind Tunnel That Achieves Supersonic Speeds with a Vacuum System
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
September, 1966. On the Making of an Inexpensive Diffraction-Grating Spectrograph
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
August, 1966. Stimulating Plant Growth with Ultrasonic Vibrations; Electrical Discharges in a Gas
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
July, 1966. An Inexpensive Machine to Record Observational Data Automatically
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1966. How to Build a Gas Chromatograph and Use It to Separate the Components of Mixtures
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1966. A Rain Gauge, a Fluid Flip-Flop, a Sundial and a Way of Seeing Crystals As They Grow
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
April, 1966. How to Perform Experiments with Animal Cells Living in Tissue Culture
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
March, 1966. On Preserving the Shapes of Snow Crystals, By Catching Snowflakes in Dissolved Plastic
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
February, 1966. How to Record and Listen to the Electrical Signals Produced By Microscopic Animals
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1966. How to Cultivate the Slime Molds and Perform Experiments on Them
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1965
 

December, 1965. Deep Sky Photographs with a 35-Millimeter Camera and More about the Homemade Laser
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
November, 1965. How to Isolate From Samples of Topsoil Microorganisms That Secrete Antibiotics
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1965. An Electrometer, a Temperature Control Apparatus, and a Simple Electric Motor
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1965. An Apparatus for Simulating High Altitudes and Testing Their Effects on Small Animals
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
August, 1965. How to Measure Raindrops, Make Snowflakes, and Simulate Subatomic Particle Scattering
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1965. The Semiconducting "Hall Device" Opens Up a Broad New Field of Experimentation
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1965. How to Study the Genetics of Fruit Flies with Chromatograms Viewed By Ultraviolet Lamp
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1965. Zany Mechanical Devices That Draw the Figures Knows As Harmonograms
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
April, 1965. How the Amateur Can Identify Subatomic Particles From Their Tracks in Photographs
Cost:NA	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1965. On Collecting and Preserving Animals That Live Along the Edge of the Sea
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
February, 1965. On Constructing and Using a Photoelectric Colorimeter for Various Chemical Analyses
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1965. On a Paradoxical Pump, Reversing Cubes, Vortex Rings, and Various Other Matters
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1964
 

December, 1964. Mainly on Simulating Gravitational Fields with Droplets of Water on a Soap Bubble
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
November, 1964. Moire Patterns Provide Both Recreation and Some Analogues for Solving Problems
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1964. Experiments in Phototaxis: the Response of Organisms to Changes in Illumination
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1964. How a Persevering Amateur Can Build a Gas Laser in the Home
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
August, 1964. Extraction of Growth Promoting Substances From Cantaloupe; Tests with Rolling Balls
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
July, 1964. On Constructing High-Speed Cameras for Photographing Fleeting Events
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
June, 1964. How to Make a Series Interferometer to Observe Various Subtle Phenomena
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1964. Blowing Glass for the Amateur Laboratory Is Really Not As Difficult As It May Seem
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
April, 1964. A Tuning Fork with Electric Drive Can Make an Inexpensive and Highly Accurate Clock
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
March, 1964. Two Devices for Listening in on Underwater Sound, and a Sundial That Tells Clock Time
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
February, 1964. How to Photograph Air Currents in Color and Build an Accurate Foucault Pendulum
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1964. The Dynamics of a Golf Club and the Aerodynamics of Air-Supported Vehicles
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:

1963
 

December, 1963. Some Experiments on the Effects of Ionizing Radiation on Plants
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
November, 1963. How to Grind, Polish and Test an Aluminum Telescope Mirror
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1963. How to Make and Investigate Vortexes in Water and Flame
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
September, 1963. How to Repeat Cavendish's Experiment for Determining the Constant of Gravity
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
August, 1963. A Large Telescope for a Home Observatory and a Light Meter for Use in the Darkroom
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1963. How to Generate Free Radicals and Collect Them for Analysis
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
June, 1963. A Simple Analogue Computer That Simulates Pavlov's Dogs
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1963. How to Locate a Thunderstorm and Track It By Detecting the Radio Waves It Generates: Moire Patterns
Cost:$0-100	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
April, 1963. How to Construct a Stream Table to Simulate Geological Processes
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1963. How to Make a Highly Accurate Clock That Utilizes Tunnel Diodes
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
February, 1963. How to Collect and Preserve the Delicate Webs of Spiders
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1963. Experiments with Ptyalin Demonstrate the Basic Principles of Enzyme Action
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1962
 

December, 1962. An Apparatus for Studying the Crystallization in Solutions Frozen on a Mercury Surface
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
November, 1962. How to Build and Maintain Aquariums for Organisms That Live in the Ocean
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
October, 1962. How to Make a Ripple Tank to Examine Wave Phenomena
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
September, 1962. How to Build a Polarograph, a Sensitive Instrument for Making Chemical Analyses
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
August, 1962. How Streams of Water Can Be Used to Create Analogues of Electronic Tubes and Circuits
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
July, 1962. How an Electric Field Can Modulate Light By Changing the Refractivity of a Crystal
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1962. Analysis of Blood Serum Protiens By Means of Zone Electrophoresis
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1962. How to Study the Diffusion of Liquids and a Sensitive Exposure Meter
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
April, 1962. Experiments with a Plant Growth Inhibitor and a Report on a Fixed-Eyepiece Telescope
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1962. Growing Crystals in Silica Gel Mimics Natural Mineralization
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
February, 1962. About Two a Radio Telescopes That Were Made By Amateurs
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
January, 1962. How to Make an Electrocardiogram of a Water Flea and Investigate Other Bioelectric Effects
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

1961
 

December, 1961. A New Method That Enables the Amateur Minerologist to Identify Various Clays
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
November, 1961. A High School Student Builds a Plasma Jet Generator That Attains Solar Temperatures
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
October, 1961. An Amateur Investigates the Origins of Venezuela's Peculiar Fog: the Calina
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1961. How the Amateur Can Experiment with Films Only One Molecule Thick
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
August, 1961. Some Diverting Devices That Apply the Concept of Negative Resistance
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1961. An Amateur Uses Paper Chromatography to Separate the Constituents of Mixtures
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
June, 1961. An Amateur's Improved Design for a Homemade Quartz Crystal Clock
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1961. Mostly on How to Make Impressions of Biological Specimins in Plastic
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
April, 1961. Various Experiments for a Rainy Weekend
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1961. A Young Amateur Experiments with a Plant That Collapses Its Leaves When Touched
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
February, 1961. Concerning Periscopes, High Vacuums, Microprojection and Photomicrography
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
January, 1961. An Amateur Makes Spectra of the Aurora and Photographs the Sun's "Green Flash"
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:

1960
 

December, 1960. Two Amateurs Calculate the Exposure Needed to Photograph a Lunar Eclipse
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
November, 1960. How to Make an Electret: the Device That Permanently Maintains an Electric Charge
Cost:$0-100	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:
October, 1960. How Amateurs Can Make a Device for Listening to Underwater Sounds
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
September, 1960. How a Group of Amateurs Detected Flares on the Sun with Long-Wave Radio Receivers
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
August, 1960. A Second Article about How Two Amateurs Refined the Accuracy of a Pendulum Clock
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1960. How Two Distinguished Amateurs Set about Refining the Accuracy of a Pendulum Clock
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
June, 1960. Concerning Experiments with Rubber and How to Re-Create a Classical Electrostatic Generator
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
May, 1960. How the Amateur Can Perform Experiments That Call for the Use of Radioactive Isotopes
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
April, 1960. Apparatus to Measure the Coriolis Force, and How to Make a Kymograph Out of a Tin Can
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
March, 1960. Concerning Homemade Vacuum Pumps and Some of the Things That Can Be Done with Them
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
February, 1960. An Amateur Asks: Does a Hummingbird Find Its Way to Nectar Through Its Sense of Smell?
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1960. How a Group of Amateurs, with Professional Guidance, Unearthed an Early Indian Village
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility: