The purpose of this annual sacrifice was evidently to secure fertility and prosperity generally, and we refer to it here so fully because of the light it throws on the Indian ceremonial which it resembles closely in some of its details. There are two direct references to the horse sacrifice in the _Rigveda_.[141] The animal is “covered with rich trappings” and led thrice round the altar. It is accompanied by a goat, which is killed first to “announce the sacrifice to the gods”. A goat was also slain at a burial to inform the gods that the soul was about to enter Heaven. [141] _Rigveda_, i, 162, and i, 163. In the _Story of Nala_ and in the _Ramáyana_, the horse sacrifice is performed to secure human offspring. A second _Ramáyana_ horse sacrifice is offered as an atonement after the slaying of the demon Ravana. An elaborate account of this great ceremonial is also given in the _Mahábhárata_. It was performed after “the great war” on the advice of the sage Vyasa to atone for the slaying of kinsmen. The horse was let loose and an army followed it. Whichever country the animal entered had to be conquered for the owner of the horse, so that only a powerful monarch could fulfil the conditions of the sacrifice. A hundred such sacrifices might enable a king to depose Indra. It is significant, however, that the animal was released to wander from kingdom to kingdom on the night of the full moon in the spring month of Choitro, and that it returned in the following year at the close of the winter season. When the ground was prepared by being ploughed by the king, the queen followed him, sowing the seeds of every kind of vegetable and curative herb which grew in the kingdom. A countless number of representative animals were sacrificed before the sacred horse was slain, the rain drum and trumpet were sounded, and the king and queen were drenched with holy water. The flesh of the horse was cooked and eaten, and Indra and the other gods appeared and partook of their portions. Pieces were also flung in the fire, and the fire received also its meed of Soma. When the sacrifice was completed, the king divided the herb offerings among the people; what remained over was burned. In the _Mahábhárata_ a white horse is sacrificed, but in the _Ramáyana_ a black victim is offered up. White horses were sacrificed to Mars by the Romans; the Greeks sacrificed white horses to the sun by throwing them in the sea; the Spartans offered up their horses, like the Buriats, on a hilltop.