The houses are divisions of the heavens relative to the birthplace, and the signs are divisions of the heavens relative to the vernal equinox. The Zodiac appears to move at the rate of one degree in every four minutes, but the Houses are considered stationary relative to the birthplace.
The birthplace is always considered the highest place on earth. And from that point four imaginary lines are drawn to the four cardinal points, North, East, South and West. Imagine a line drawn from your birthplace to the point directly overhead where the Sun is at noon. That would be directly South, and this line is regarded as the cusp of the Tenth House, which for that reason is called the midheaven. If this line is extended through the center of the earth, to the opposite side of the earth and thence into space, that lower part would point North, and form the cusp of the Fourth House called the Nadir, which is opposite the Tenth.
An astrological Figure is divided into 12 arcs, equal either in terms of space or time. If in terms of space the arcs are of 30° each, one twelfth of the circle of 360°. If these begin at 0° Aries they are known as the Signs of the Zodiac, from Aries to Pisces, and represent subdivisions of the orbit of the Earth round the Sun. As such they are Signs, not Houses. They bear no relation to the constellations after which they were anciently named, but are measured from the Spring equinoctial point.
If the subdivision begins at a given moment, and each represents the celestial arc that passes over the horizon ill 2 hours -- one twelfth of the time required for one complete rotation -- the divisions are known as Houses.
In considering the divisions of the Figure as consisting of Signs, the Figure is deemed to stand still while one contemplates the actual motions of the planets in their orbits round the Sun, in a counter-clockwise direction. In considering the divisions as Houses, the observer deems the planets to stand still while the Figure (represent- ing the Earth) rotates in a counter-clockwise direction, thus causing the planets to appear to move in a clockwise direction at a uniform rate, one after another passing from below the horizon to above it, and on through the Midheaven to the Descendant, just as the Sun rises and sets.
There are also Solar Houses-subdivisions of a Figure which, because the moment of inception, otherwise "birth-moment," is unknown-cast with the Sun's degree at Greenwich noon as the Rising Degree, or Ascendant. In the House-divisions so determined are placed the planets in the positions they tenanted at Greenwich noon on that particular date.
In any event one should at all times bear in mind that the Signs are divisions of an annual cycle, beginning with the Spring Equinox; while the Houses arc divisions of a daily cycle of apparent motions resulting from the Earth's own daily rotation on its axis. Some modern authorities employ the term Heliarc in lieu of Sign as a subdivision of the Earth's annual orbit, and Geoarc in lieu of House as the subdivision of the orbit of a given point on the Earth's periphery round the axis -- hence a subdivision of the Earth's daily rotation.
Thus the influence of the Sign-positions, and the pattern of con- figurations resulting from the places the planets occupy therein, are a common experience of everyone born anywhere on the Earth's surface upon that day; but the point at which a personality enters into this cycle is an individual factor which determines the "angle of incidence" at which these cosmic impulses impinge upon his own consciousness.
These two points are invested by the same degrees of the Zodiac, at any given time regardless of whether the birthplace is near the pole or the equator. In the latter case, we may also imagine a line drawn at right angles across the Meridian, (as the line in the horoscope from the Midheaven to the Nadir is called), from East to West, and that would then form the cusps of the First and Seventh Houses. By dividing each of the four sections into three we would have twelve compartments of equal size, namely thirty degrees each.
But all birthplaces are not on the equator, and owing to the spherical shape of the earth and the inclination of the earth's axis, the sizes of the houses vary more and more as we approach the poles, so that some houses may have only twelve or fifteen degrees, while others have more than sixty.
The reason for this division of the earth into houses may be comprehended when we consider that the Sun's rays affect us differently in the morning, at noon and at night, also in summer and winter; and if we study the cause, we shall readily see that it is the angle at which the ray strikes us or the earth which produces the difference in effect. Similarly with the stellar rays, Astrologers have observed that a child born at or near noon, when the Sun's rays strike the birthplace from the Tenth House, has a better chance of advancement in life, other things being equal, than one born after Sundown, for the latter generally remains a servant.
Therefore they say that the Tenth House determines social position and honor, but the Sixth House, which is just below the Western horizon rules service and employment. By similar observations and tabulations it has been found that the other planetary rays affect the various departments of life when their ray is projected through the other houses, and therefore each house is said to 'rule' certain things.
The divisions of houses are sometimes called 'mundane' houses; and the signs of the Zodiac are also loosely spoken of as the 'houses' or 'homes,' of the plants which rule them, for instance, Virgo is the 'house' of Mercury, Capricorn is the 'home' of Saturn.