Dr. Dethier explains his research for the perfect insect repellent. He discusses and gives examples of the five qualities of a perfect repellent: odorless, inexpensive, non-toxic, cosmetically acceptable, and effective for extended periods of time. Using a diagram of a blowfly's anatomy, Dr. Dethier explains how the flies are used in repellent research. Then using a series of actual flies, their wings waxed to sticks, Dr. Dethier puts the feet of the fly successively into sugar water, .01% glycol and sugar, and .1% glycol and sugar to observe the fly's reaction. The result is generally the average of a 100-fly test. Dr. Dethier then shows how one can predict the feasibility of some chemical compounds as repellents by their composition. He constructs a graph and using aldehydes, plots the repellent effect in relation to the size of the compound's molecules.

Howard Owens, of Northwestern High School in Prince Georges County, MD, briefly discusses the purpose of the National Science Fair. Talented students then display and explain their Science Fair projects. Don Boyle experiments with the effects of radio waves on seed germination. Mary Catherine White reconstructs a functioning battery using Volta's methods. Gary Miggs creates a diorama based on the fossils characteristic of the Devonian Period. Jean Spencer determines the amount of black widow spider venom required to kill a white mouse. Fred Shindler researches the life cycle of the corn borer in an unsuccessful attempt to break that cycle and thus eradicate the pest.

The brain perceives not only what is seen by the eyes, but also processes experience and expectations to sometimes perceive not exactly what was seen. Magic tricks depend on the perception of the eye. Optical illusions and moving picture frames show that the eye can be tricked. The ability to detect movement is relative, but eyes can determine distance by working together.

There are 234 muscles in the human body which interpret signals from the nervous system to perform simple and complex operations. Pairs of muscles often work together by expanding and contracting in opposition to each other to perform at optimum efficiency. Muscle contraction consists of physical, chemical, and electrical changes.

Determining the levels of hearing loss in young children can be measured by noting the child's reactions to various levels of volume and pitch. The key to treating hearing impairments in children is the early detection of hearing loss. Training parents to work with deaf children and the early fitting of hearing aids is important in the development of communication skills.

In this second in a series of programs on space exploration, Francis Clauser discusses how Newton's third law explains the propulsion of rocket ships. Speeds of over 25,000 miles per hour are needed to escape the earth's atmosphere and 16,000 miles per hour to put a rocket in orbit around the earth. Fuels that can be used to propel rockets include hydrazine and nitric acid. A model of a three stage rocket is shown to demonstrate how man will begin space travel.

Scientific research often requires specially made equipment. The glass blower can make intricate apparatuses designed to exacting specifications that are used in scientific laboratories for specific research purposes. Master glass blower John Lehman demonstrates this by making a hydrogenation apparatus that can turn vegetable oils into solid shortening. The first cathode ray tubes used in early television were created by glass blowers.

The program begins with a discussion of the solar system with the sun in the center and the nine planets, with their satellites or moons. Comets also travel around the sun in very irregular orbits. Great clusters of billions of stars form galaxies. The earth is near the center of the galaxy known as the Milky Way. Stars are arranged into the constellations that have distinctive configurations.

The life cycle of the butterfly goes through metamorphosis by changing from eggs to larvae to caterpillars to pupae to butterflies. Various species of butterflies and their anatomy, variety, and migration are discussed along with the fact that many cultures around the world eat butterflies and caterpillars.

Most pollsters incorrectly predicted the 1948 United States presidential election. Political scientists try to determine political trends in the U.S. by tracking the party affiliation of the House of Representatives. Local and regional differences can be seen by analyzing election results over the years. Most states show trends that mirror overall national results. Analysis of these factors can help predict future elections.