Rational Horizon

Rational Horizon, a great circle parallel to the horizon, the centre of which is the centre of the earth.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Ratich, Wolfgang * Rationalism, Modern
Rashi
Rask, Rasmus Christian
Raskolink
Raspail, François Vincent
Rassam, Hormuzd
Rasselas
Rastatt
Rataña
Rathlin
Ratich, Wolfgang
Rational Horizon
Rationalism, Modern
Ratisbo
Rattazzi, Urbano
Rauch, Christian
Rauhes Haus
Raumer, Friedrich Ludwig Georg von
Ravaillac, François
Ravana
Ravenna
Ravenna, Exarch of