ἐν πέτροισι πέτρον. For the change of quantity, cp. 827 (“ὕπνε”): O. C. 442“οἱ τοῦ πατρὸς τω? πατρὶ”: ib. 883 “ἆρ᾽ οὐχ ὕβρις τάδ̓;—ὕβρις”: Ant. 1310 f. “δείλαι^ος...—δειλαίᾳ”: El. 148“ἃ Ἴτυν, αἰὲν Ἴτυν ὀλοφύρεται.” ἐκτρίβων, rubbing hard (“ἐκ”=‘thoroughly,’ i.e. till the spark comes). The v. l. “ἐκθλίβων” would mean, ‘pressing’ or ‘squeezing,’ and is unsuitable. Cp. Xen. Cyr. 2. 2. 15“ἔκ γε σοῦ πῦρ...ῥᾷον ἄν τις ἐκτρίψειεν ἢ γέλωτα ἐξαγάγοιτο”. The use of two stones would suggest concussion rather than friction. The Eskimos kindle fire by striking a piece of iron pyrites with a piece of quartz (instead of flint); the Alaskans of North America, and the Aleutian islanders (in the North Pacific), use two pieces of quartz, smeared with native sulphur. (M. Elie Reclus, in Encycl. Brit., art. ‘Fire.’) ἐκτρίβων might, however, cover the case of a slanting or scraping blow. In Lucian Ver. Hist. 1. 32 “τὰ πυρεῖα συντρίψαντες” refers to rubbing sticks together. ἔφην᾽ ἄφαντον φῶς, made the invisible light visible, i.e. drew the spark forth from its hiding place in the stone. Cp. Ai. 647(Time) “φύει τ᾽ ἄδηλα καὶ φανέντα κρύπτεται”. Blaydes compares Synesius Ep. 138 “σπινθῆρα κεκρυμμένον καὶ ἀγαπῶντα λανθάνειν”. G. 1. 135 Ut silicis venis abstrusum excuderet ignem. ἄφαντον could hardly be, ‘barely seen,’ as if the sense were that the feeble spark instantly vanished again.