they had held previous discussions of course , chiefly during their long car ride together back to essex after the wotinabee conference , a ride that had been protracted considerably by professor antwhistle 's predilection for short-cuts , diversionary trips , and innumerable stops for snacks or interesting vistas , not to mention the untrustworthy state of his automobile which punctuated the voyage further with several unscheduled visits to service stations .