ἀνὰ [6 verses](prep) "On"  is ana, which is a preposition that with the genitive, means "on board" a ship.With accusative, implies upward motion; of place, "from bottom to top" or "up along;" of time, "throughout;" of mind, "to have continually" in mind, " as an adverb, "thereupon," "throughout," "all over," "up," and "arising. -- "By" is from an uncommon prepositions that means on board (a ship),"  "upon," of Place: "up," "from bottom to top," "up along," of Time, "throughout," and, metaphorically, "continually in," "in," and "among." The sense here is "up to."