Unitary space transit

Abstract

Abstract An instrument is provided which requires no complex computations or high degree of skill in aligning scales to accurately indicate the time of day from observations of the position of the sun, and to accurately locate the moon, the sun, and other stars and constellations in celestial space. The instrument comprises a vertically adjustable stand upon which is mounted a support plane which may be rotated about a horizontal axis to accommodate alignment with the celestial equator. To the support plate is mounted a single rotary disk rotatable about a principal axis normal to the plane of the support plate. Inscribed upon the surface of the disk are an hour scale, a month-day scale, a right ascension hour angle scale, a local hour angle scale, a moon phase scale, a lunation scale to trace the phases of the moon, and a zodiac constellation display. Integrally formed from and normal to the disk are a sunbeam aperture plate, a sunbeam trace plate, and a plate having a declination scale inscribed thereon and to which a space object pointer with a bubble level is rotatably attached. Inscribed on the surface of the sunbeam trace plate opposite the aperture plate are time equation graphs tracing the movement of the sun in both the northern and southern celestial hemispheres. Sun declination scales and mean sun base lines corresponding to each time graph are also inscribed on the trace plate. When the support plate is aligned with its face toward the north and parallel to the plane of the celestial equator, the rotary disk may be turned to a position where sunlight passes through an aperture of the sunbeam aperture plate to strike a time equation graph or a mean sun base line inscribed on the trace plate. A rotary meridian marker mounted to the support plate so as to rotate about its principal axis independent of the rotary disk may then be used to directly indicate standard time, daylight saving time, solar time, or mean solar time on the hour scale. To function as a space transit, the rotary disk may be adjusted for longitudinal correction and right ascension, and the space object pointer may be adjusted for declination to locate the moon, sun, planets and other stars and constellations in space. Conversely, after the instrument has been directed toward an object in space, the instrument may be adjusted to indicate the right ascension and declination of the object. In addition, the constellations of the zodiac may be more generally located by means of the zodiac constellation display and a knowledge of the sun's declination during the month of concern. The moon phase and lunation interval scales make possible the tracing of any moon phase throughout the current and subsequent years. Further, when the date of the moon phase is determined, the right ascension and hour angle of the moon at any given time during the phase may be acquired.

Inventors

• 👤 Ralph Troseth

Bibliographic Details