Nine augures were specialists assisting magistrates in taking the auspices and advising the Senate and the magistrates on various aspects of divination, not the least of which was the proper handling of prodigies and portents. They also created templa, or sacred spaces.
Origins and historical development
The College of augurs kept records of "...the veteres res, that is, those signs the meaning of which had been established already in the (remote) past empirically through the process of long-continued observation (observatio diuturna)-those signs were recorded in the books of the augurs, their meaning codified once and for ever;..."
We can see an example of this function in Dionysius of Halicarnasus.
"But some relate that the ancestors of the Romans from very early times, even before they had learned it from the Tyrrhenians, looked upon the lightning that came from the left as a favourable omen. For ... Ascanius, ..., his situation being now desperate, he prayed [for] favourable omens, and thereupon out of a clear sky there appeared a flash of lightning coming from the left; and as this battle had the happiest outcome, this sign continued to be regarded as favourable by his posterity."
The correlation of the omen (lightning on the left) in "very early times" with the positive outcome was noted and it became enshrined as a principle of Roman augury.
Linderski, J. 1982. "Auspicia et Auguria Romana... Summo Labore Collecta": A Note on Minucius Felix Octavius 26.1. Classical Philology, Vol. 77, No. 2 (Apr., 1982), pp. 148-150. The University of Chicago Press (Retrieve from JSTOR)
- Augures in Nova Roma