Abstract: A mechanical method is described whereby the brake signal provided by the rear lights of an automotive vehicle is made unambiguous. In the case that the brake pedal of the said vehicle is not actuated, the invention causes all light from illuminated rear lamps of the vehicle to be transmitted from the rear of the vehicle as non-red colored light. In the case that the brake actuation means of the vehicle is actuated, the invention causes all light from illuminated rear lamps to be transmitted from the rear of the vehicle as red colored light. Thus, display of red colored light per se at the rear of the vehicle provides an absolute, immediately perceptible signal of braking.

Abstract: Confusion of red colored automotive brake signal lights with other red lights delays perception of the brake signal. Perceptibility of the brake signal is improved when red colored lights are displayed only during braking, non-red colored lights being displayed at appropriate other times. The current invention effects this color distinction by interposing, during braking, low electric resistance into electric circuits between a source of electrical energy and lamps effecting red colored light, and interposing high electric resistance into electric circuits between said source of electrical energy and lamps effecting non-red colored light, and further, by interchanging the said interposed electric resistances when the brake actuation means is not actuated, flow of energizing electric current being sufficient to effect illumination of said lamps only in the case that said interposed electric resistance is low.

Abstract: An electronic calculator having unique utility for computation in chemical stoichiometry is described. Push-bottom input keys for stoichiometry are labeled by chemical unit, each of said keys being juxtaposed to an LED indicator light, and said keys being apportioned by line segments on the keyboard into five functional groups. The stoichiometry keys utilize variable conversion factors input by the user to automatically effect arithmetic conversion of a number, input with its chemical unit, into the equivalent number having a different chemical unit, said units being implicitly displayed by illumination of appropriate LED's. For students and others, the invention greatly simplifies the task of computation in chemical stoichiometry.

Abstract: Delayed perception of the brake signal, a significant contributing factor in many rear-end automotive vehicle collisions, is a problem not totally resolved by the addition of a red colored supplementary brake signal light. A more effective and esthetically superior approach is employed in the current invention, in which red colored light, and only red colored light, is displayed at the rear of a vehicle during braking; and further, in which non-red colored light, and only non-red colored light, can be displayed at the rear of said vehicle when the brake actuation means is not actuated. If illuminated, non-red tail lights and rear turn signal lights are extinguished during braking, replaced by red colored brake signal lights, one of which may flash to indicate an intended turn, said red colored lights being extinguished and said non-red colored lights being re-illuminated upon release of the brake actuation means.