Atmosphere
 

September, 1999. Counting Atmospheric Ions
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
July, 1999. Detecting the Earth's Electricity
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
April, 1999. Detecting "Hot" Clouds
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
June, 1998. Waiter, There's a Hair in My Hygrometer
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1998. Detecting Subtle Tsunamis
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
August, 1997. Getting a Charge Out of Rain
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1997. When Hazy Skies Are Rising
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
November, 1995. Measuring the Wind with Hot Metal
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
April, 1987. Making a Barometer That Works with Water in Place of Mercury
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
January, 1985. Searching for Patterns of Rainfall in a Storm
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1980. Billows in the Ionosphere Are Tracked with Transistor Radios
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
June, 1980. Mysteries of Rainbows, Notably Their Rare Supernumerary Arcs
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
May, 1978. What Plumes of Smoke Tell about the Structure of the Atmosphere
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1974. Weather-Satellite Pictures Are Picked Up in the Home
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
June, 1972. Outdoor Temperature, Humidity, Wind Speed and Wind Direction Are Displayed on a Panel
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1971. Experiments with Wind: a Pendulum Anemometer and Miniature Tornadoes
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	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:
March, 1966. On Preserving the Shapes of Snow Crystals, By Catching Snowflakes in Dissolved Plastic
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:
October, 1961. An Amateur Investigates the Origins of Venezuela's Peculiar Fog: the Calina
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	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, 1959. How Short Term Weather Forecasts Were Made on the Basis of Electrical Effects
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1954. About a Hygrometer Made From a Flower Pot, and Huge Telescopes with Compound Mirrors
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1953. On the Nationwide Net of Weather Observers and the Ruling of a Grating on a Cylinder
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:

Ecology
 

May, 1993. Mapping to Preserve a Watershed
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1993. Biodiversity in the Backyard
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

Geology
 

April, 1996. The New Backyard Seismology
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
May, 1988. Icicles Ensheathe a Number of Puzzles: Just How Does the Water Freeze?
Cost:NA	Difficulty: NA	Danger 0: (NA)	Utility:
August, 1982. Walking on the Shore, Watching the Waves and Thinking on How They Shape the Beach
Cost:NA	Difficulty: NA	Danger 0: (NA)	Utility:
January, 1982. Why Do Particles of Sand and Mud Stick Together When They Are Wet
Cost:NA	Difficulty: NA	Danger 0: (NA)	Utility:
July, 1979. How to Build a Simple Seismograph to Record Earthquake Waves At Home
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1975. Electronic Stratagems Are the Key to Making a Sensitive Seismometer
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
November, 1973. A Sensitive Tiltmeter That Serves As a Seismometer
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
April, 1963. How to Construct a Stream Table to Simulate Geological Processes
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
July, 1957. Concerning Simple and Ingenious Devices to Record the Waves Made By Earthquakes
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
June, 1953. About an Ingenious Electronic Seismograph and the Observation of Changes on the Moon
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
November, 1952. The Study of Rocks and the Making of Two Relatively Simple Telescopes
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
June, 1952. Mountain Geology and an Amateur Contribution to a New Ruling Engine
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
April, 1952. Larkin's Sprengnether Seismometer
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:

Lab Techniques
 

September, 2000. Using a Kite as an Experimental Platform
Cost:$0-100	Difficulty:	Danger 1: (No Hazards)	Utility:
May, 1979. How to Measure the Size of the Earth with Only a Foot Rule or a Stopwatch
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
August, 1970. Devices for Listening to Sounds Both in Water and in the Solid Earth
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:

Limnology
 

August, 1998. Building a Consciousness of Streams
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
September, 1996. The Pleasures of Exploring Ponds
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
August, 1994. Scanning Underwater Surfaces
Cost:$100+	Difficulty:	Danger 2: (Minor injury possible)	Utility:
October, 1972. An Observatory Built in a Pond Provides a Good View of Aquatic Animals and Plants
Cost:$100+	Difficulty:	Danger 3: (Serious injury possible)	Utility:
March, 1970. How to Study the Life of a Pond and to Cultivate Aquatic Insects
Cost:$0-100	Difficulty:	Danger 3: (Serious 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:
October, 1960. How Amateurs Can Make a Device for Listening to Underwater Sounds
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:

Mineralogy
 

March, 1962. Growing Crystals in Silica Gel Mimics Natural Mineralization
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
December, 1961. A New Method That Enables the Amateur Minerologist to Identify Various Clays
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
February, 1955. About Tiny Mineral Specimens and Other Matters, Including a Troublesome Puzzle
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:

Oceanography
 

November, 1998. Floating a Challenge
Cost:$100+	Difficulty:	Danger 1: (No hazards)	Utility:
July, 1998. A Year for the Oceans
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	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:
August, 1953. On the Popular Diversion of Free Diving, and a Well-Built Cassegrain Telescope
Cost:$100+	Difficulty:	Danger 4: (POSSIBLY LETHAL!!)	Utility:

Paleontology
 

March, 1980. Stalking the Fossil Trilobite, Crinoid, and Seed Fern in Ohio
Cost:$0-100	Difficulty:	Danger 3: (Serious injury possible)	Utility:
February, 1959. Mostly about Unearthing the Fossils of Dinosaurs
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
October, 1956. Fossil Starfish From Iowa and a British Van De Graaf
Cost:$0-100	Difficulty:	Danger 2: (Minor injury possible)	Utility:
May, 1956. Mostly about the Collection and Study of Fossilized Seeds
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility:
January, 1954. About the Pleasures of Paleontology and How to Make a "Fish Eye" Camera
Cost:$0-100	Difficulty:	Danger 1: (No hazards)	Utility: