This is subject to an equation depending on the position of the planet in its orbit, and it determines the difference between the imaginary planet and the true planet.The equation itself depends on the eccentricity of the orbit, that is to say, its relation to a circle drawn around the same focal centre.
Not that these discoveries overturned the whole system of astrology, as some have imagined and foolishly stated, or that they negatived the conclusions drawn from the observed effects of the seven anciently known bodies of the solar system, but it became possible after a lapse of time to fill in the blank spaces and to account for certain events which had not been traced to the action of any of the already known planets.
It is believed that the present work will be of considerable assistance to those who seriously contemplate an initial study of the science of horoscopy, and although it by no means exhausts what is known on the subject, yet it will be found accurate and reliable as far as it goes, and will enable any one of ordinary intelligence to test the claims of Astrology for himself.
This is as much as can be expected in the limits of a small handbook.
Neptune revolves around the Sun in its distant orbit once in about 165 years.
Uranus completes its orbital revolution in 84 years, Jupiter in 12 years, Mars in about 15 months, Venus in 11 months, and Mercury in 18 weeks.