Section five lists main dealer locations and main branch offices by region and state. Canada and Puerto Rico are included in this section. Following each state or country, the listings are alphabetical by city. Addresses are given. (MA)

Describes an inexpensive photo transistor timing system, apparatus for measuring muzzle velocity, and an apparatus for exposing modes of coupled oscillators. (SL)

Describes a modification to the Jensen and Edwards model current balance utilized in elementary physics laboratories which improves operation and ease of maintenance. (SL)

Explains the use of a convex lens as a thick mirror. Shows the expression for the power of this type mirror. (YP)

Described is the use of a microcomputer and computer software to simulate the use of geological equipment. The technique uses pictures of the control panel (with switches and dials that can be activated) and a story board that can provide the simulation. A simple seismograph is used as an example of possible simulations. (RH)

Explains two activities: (1) a "rotator demonstration" (a turntable, pendulum, chalk, and other materials), which can be used in many activities to demonstrate rotational concepts; and (2) an "Eskimo yo-yo," consisting of two balls (plus long strings and a glass tube) which rotate in opposite directions to show centripetal force. (JN)

The construction of a diffraction grating spectroscope has been previously reported. A procedure to fit a linear scale to this spectroscope is described (allowing measurement on wavelength of spectral lines without increasing cost of the assembly). Also described are some applications of this modified spectroscope for secondary school laboratory…

Describes a demonstration involving the controlled combustion of a mixture of metals with black and smokeless powder in a small Erlenmeyer flask. Also describes demonstrations using a device that precludes breathing of hazardous vapors during class demonstrations; the device is easy to transport and use in rooms without sinks. (JN)

Discusses various topics related to the interfacing of computers, focusing particularly on methods of data collection using instruments. Topics include serial digital connections (examining RS 232C and V.24, physical protocol, electrical protocol, and other areas) and parallel digital connections. (JN)

Provides instructions for making tin can radiation detectors from empty aluminum cans, aluminum foil, clear plastic, copper wire, silica gel, and fine, unwaxed dental floss put together with tape or glue. Also provides suggestions for activities using the detectors. (JN)

The Apple game port has two types of inputs: the paddle input and the button input. Scientific applications of these input-output units are discussed, examining analog inputs (potentiometers, thermistors, and photoresistors), single bit digital inputs, and single-bit outputs. (JN)

Discusses various activities using a ripple tank. Offers practical suggestions (not mentioned in standard textbooks) for achieving a clear, steady quality of waves with the instrument. (JN)

Shows how the rate of reaction can be studied using a simple electronic device that overcomes the difficulty students encounter in solving the differential equations describing chemical equilibrium. The device, used in conjunction with an oscilloscope, supplies the voltages that represent the chemical variables that take part in the equilibrium.…

Describes: (1) a FORTH-language, computer-controlled potentiometric titration; (2) coulometric titrations using computer-interfaced potentiometric endpoint detection; (3) interfacing a scanning infrared spectrophotometer to a microcomputer; (4) demonstrations of signal-to-noise enhancement (digital filtering); (5) and an inexpensive Apple…

Describes: (1) experiments using a simple phonocardiograph; (2) radioactivity experiments involving a VELA used as a ratemeter; (3) a 25cm continuously operating Foucault pendulum; and (4) camera control of experiments. Descriptions of equipment needed are provided when applicable. (JN)