The Fourth and Tenth Houses – Roots and Limbs
Look straight up, and then look straight down.  What you just saw – but probably never knew was there – was the Midhaven and the Nadir; the highest and lowest point of the sky.  These two objects form the second and final angle, the Fourth/Tenth house line.  

Astrology’s second act of division is that between where we came from and where we are going.  The Fourth and Tenth house line shows where we came from and where we are going in life; like the roots and limbs of a tree.  Does this mean that destiny is fixed?  Not at all: we are just like a tree.  Our roots are firmly planted (there’s no changing where you came from), but our branches are free to grow in whatever direction we wish them too.  All astrology can do is show us what areas we could excel or be more comfortable in, we can take the advice of the stars, or leave it.

The Fourth House Dissected
The Fourth house is said to rule that from which we came.  Specifically the Fourth house rules our fathers (fathers being associated with ancestry as a child generally takes their father’s name), houses, and domestic environment, as well as the ‘land under our feet’ in which the context points to our home country or town (this house also rules ancestry, and personally, my Fourth house is in Gemini while the ruler of this house is in Leo, I’m of Italian descent, and Leo is associated with Italy).  All matter of lands and the quality of the lands (whether barren, fertile, rocky, etc), and that which is hidden beneath these lands.  This house has an intimate connection with agriculture, as it relates to lands, and all growing crops are found here.  The Fourth house is also a dual-sided house, ruling both the beginning and end of all things as is associated with childhood and old age.

For co-significators, this house has the Sign Cancer and planet Sol.  The house is sometimes referred to as the northern house and is associated with the Northern direction.  Cancer is the northern-most Sign, so this connection between Sign and house seems obvious.  Sol generally is a representative of men and fathers, so his connection to this house is very significant.  It should also be noted, though, that some traditional authors called this the temple of Saturn, as both have strong connections to agriculture and ancestry.  No planet rejoices in this house.  Modern astrology holds Luna as the ruler of this house as ruler of Cancer.

The Tenth House Dissected
The MC (another term for the Tenth house medium coeli, midhaven) personifies all sorts of authority figures: officers, lawyers, judges, kings, presidents, bosses, etc.  This house is also significant of the mother as the opposite of our fathers in the Fourth.  This Tenth house also reflects our careers, how the public views us, and our honor and reputation.  The Tenth house can be called the house of destiny, as it shows where we are headed and in what way the public looks on this; our fame or infamy and anything of that sort.  

For co-significators, the Tenth house enjoys the Sign Capricorn and the planet Mars.  The Tenth house is the house farthest South, and Capricorn the southern-most Sign, so it was only a matter of time before they became associated with one another.  No planet is said to rejoice in this house and modern astrology holds Saturn as the ruler of Capricorn.