ὅσον ἀπὸ τοῦ ἱεροῦ ἐφεωρᾶτο τῆς νήσου → as much of the island as was in view from the temple
useful: P. and V. χρήσιμος, χρηστός, σύμφορος, προσφορος, Ar. and P. ὠφέλιμος, Ar. and V. ὠφέλήσιμος.