Double Cross in Double Time

I like stories that begin with a want ad, including Heinlein’s Glory Road and the recent movie Safety Not Guaranteed. This is the earliest such story that I’ve seen, in which Paddy Donovan answers the ad (just off Fourth Avenue) to find Professor O’Neill, the professor’s angelic daughter, and a machine that stimulates a man’s dormant ability to travel through time. So, after a quick jaunt to ancient Egypt, Paddy offers to bankroll the development of the time machine’s business potential.